These with my Cowon J3 playing FLAC is just amazing. I wanted a simple portable setup and this is it.
After experimenting with tips I settled on the Shure Olives. The complys were killing the treble and fell off easily. These preserve all the treble, and if i'm not mistaken, the bass is even punchier. Also, they stick on like crazy. It's really hard to get those tips off. But that's awesome for me as I am an on-the-go student who bikes a lot.
 
The Westone 3s with the Shure Olives sound great for every genre, but I am continually amazed at how great my FLAC trance compilations sound. A State of Trance et al are perfectly portrayed by these earphones. They also do an amazing job with rock, hip-hop, and the indie mixes my girlfriend makes.
I guess I'm just impressed with how well they do with trance because I like it a lot. 
 
These were my upgrade from the Senn IE8s, and they are an upgrade in every way but soundstage. And I will sacrifice one for the good of the many. I loved the IE8s when I first got them, but the lack of isolation and the rolled-off treble made me look for something else. The W3s were the answer. I bought them for $350 on Amazon, and I listen to them from when I wake up in the morning to late into the night. Basically whenever I'm not talking to someone. They are sensitive so they hiss with my macbook (not a hipster, it was a gift) but the included resistor fixes the problem. But I dont carry it around, and I only use my macbook for watching movies so its no big deal. Just saying they're sensitive so they're going to hiss if you use them with a macbook. WIth my J3 there is literally 0 hiss.
 
And aesthetically, they're amazing. Glossy black, red accents, beautifully curved bodies. They're ridiculously durable, I've put them through hell and they dont even have a scratch on them. The coiled cable feels great, and the splitter catches perfectly each twist in the cables, a secure but easily adjustable fit. Perfect for putting the cord down your back for physical activities. There is no cable noise whatsoever if you wear them like this.
 
When I get customs, I want them to be just like these. They are crazy good. I dont know how you could not like these. They were a huge upgrade over the IE8s for me, and the IE8s cost more, unless you go for a shady ebay deal like I did.
 
I love them, and I wish every earphone had these ergonomics. If these are in your price range, I highly recommend them. Now Westone has released a 4-driver Westone 4, so I would consider that too if I didn't already have these. Good luck in whatever you end up buying.

Background: When I lost my S9, I had to find a replacement. I began to look for options, noting the Cowon J3, Nationite S:flo2, and Hifiman HM-601 as possible options. Then I discounted the Hifiman for the sake of portability. I spent a long time deciding between the J3 and the S:flo2 and eventually went with the J3 for the battery life, usability, reliability, and the digital volume control, as I like to keep my player on volume level 1 and leave it there in order to preserve my hearing as a musician.
 
I just got home from a trip today and this pretty young thing was waiting for me on my desk. I loaded 30gb of FLAC and listened for an hour, then decided I had to post a review. In short, this is my new favorite mp3 player. The S9 was awesome, with a few flaws. The J3 fixes them.
 
The button placement is so much better. I can put the screen on lock, and put it in my pocket, not worrying about the tactile buttons being pressed on accident. This gives me control without having to fiddle around with unlocking the device. 
 
The MicroSDHC slot is a godsend to those with large libraries or love to discover new music. With my S9, I always wanted more space. I love to transfer new albums I haven't listened to to my player and either delete or keep them, then repeat the process. With the S9, I had to keep deleting old albums that I liked somewhat in order to keep listening to new music. I have this card (http://www.amazon.com/SanDisk-32GB-microSDHC-Memory-Package/dp/B003WGJYCY/ref=sr_1_2?ie=UTF8&qid=1294027856&sr=8-2) coming in the mail and I look forward to having 64gb of FLAC music in my pocket at all times. 
 
The speaker is alright for music, but surprisingly useful for movies and videos. Xvid videos from perfectly reputable sources (cough) look amazing on the AMOLED screen, and seeing them is the point where most ipod touch owners will acknowledge the validity of your purchase. But hearing them adds a whole new sense to the experience. Its actually a decent speaker, beating the tinnier apple speakers to my ears, and goes fairly loud. Great for showing your favorite movies or playing your favorite new track for your non-audiophile friends. 
 
The UI is just slick. I love it. It's so much cooler than the apple products I have used, customizable with user-created themes (http://iaudiophile.net/forums/forumdisplay.php?f=111) and has easy access to the J3's capabilities directly from the music and video screens. Cowon really listened to feedback it seems. This UI is just a joy to use. The S:flo2 aint got nothin on this.
 
Extra battery life - more to love. I mean seriously, 64 hours battery life for music is almost overkill. But 11 hours video on the J3's amazing screen is perfect for long commutes and trips. And who wants to worry about charging their mp3 player all the time? I watch friends having to plug their ipods in halfway through the day and smile, knowing that I could listen to music for almost 3 days straight without stopping to plug in my J3. 
 
 
 
In short, I'm loving this little miracle so much, and I'm sure it will get even better in time. It's said that Cowon players have a slight treble emphasis. I can clearly hear everything in my music with the J3 and Westone 3 earphones. So no worries about out-of-control treble - there may be a slight emphasis, but everything sounds great to me. Another note about this pairing is that the Westone 3's, which hissed slightly with my S9, have NO hiss whatsoever with the J3. I can't hear anything but the music. And it's reproduced so beautifully. With the EQ off, its just me and the music. But using BBE EQ effects, it becomes an infinitely customizable music experience, which is really nice when plugging into my friends' stereo systems.
 
Get one now and stop being indecisive. You know you want one. 

Okay, I have to leave for school in 5 minutes, so this is gonna have to be quick.

Basically, I totally love these. With my Cowon S9, everything from Armin Van Buuren to ES Posthumous sounds ridiculously amazing. The soundstage, smooth sound, and easy listenability at low volumes are the coolest parts for me.
 
Okay, I'm not going to write a real review. I just want to say I've been looking for a full-size headphone with the same strengths that can be used unamped and there isn't one. I was thinking DT990 32 ohm, but apparently even that needs an amp. The soundstage, comfort, durability (i've really tested this part, I'm an energetic ADD high school student lol) are unbeatable for this drivability. Like yeah, I could get the AD700s for the soundstage, but these have so much more going for them. I really can't describe it, but there's a sort of emotional connection I have when I listen to music with these earphones. I actually posted a thread about this and my Cowon S9, titled something like "Cowon S9 + Senn IE8 = Bliss" a couple months back because I loved this combination so much. Anyways, get this, you won't regret it.
 

This is the player I was looking for all along. Seriously, this has given me a new found respect for Cowon, as well as Korean Innovation as a whole. So, lets get to the basics.
 
Pros:
 
Audio Quality is unbelievable. Now that the price has gone down to $200, this is the best-sounding player for under $300. No compromises either, this has been compared favorably to the Sony X, which is twice the price, with fewer audio features.
 
The EQ is equally incredible. If your coming from an iPod, be prepared to start tweaking. Before, with my ipod, I had one way to play music. If it didn't sound the way I wanted it, I had to just accept it, beyond a few primitive EQ settings that usually failed to help the sound. With the S9, you have unlimited possibilities for sound tweaking and customizing. Don't like the closed-in feeling of your headphones? Use BBE Viva or make your own custom EQ with 10 levels of Surround Sound effect. Want more/less bass/treble. Easy. Say your just listening to a song, and it doesn't sound right. The Genre settings are optimized for Rock, Dance, Classic, etc and will lift you out of your depression. If there is any DAP that will convince you not to buy an amp, its this one. You will never run out of ways to improve the sound.
 
The Screen. Oh the screen. Active Matrix Organic Light Emitting Diode. I don't know how it works, and I don't care. It looks so amazing, especially with its 16 million colors. Play a colorful movie like Avatar on it, and you will be literally blown away. The new Samsung Vibrant actually includes this movie, and has the same AMOLED-type screen as the S9, but is newer and much better advertised. When they say cinema quality they aren't joking. It's so amazing that if I had the choice of watching a movie on my laptop or on my S9, I would choose the S9 every time. Your xvids will come to life. There is a 2gb file limit for videos, but it doesn't matter, as I have watched 700mb xvids on the amazing screen without complaint. If encoding video for the S9, just set AutoGK to xvid at 75% quality, and it will look amazing and be under 2gb 99% of the time. I didn't buy it for the screen, I bought it purely for audio quality and flac support. But I would be lying if I said I didn't appreciate the screen almost as much as the superior audio quality. The EQ can be used while watching movies as well, settings like BBE Headphone will add soundstage and bass without sacrificing clarity. Really amazing.
 
Codec Support - FLAC, WAV, OGG, MP3, WMA, APE. Everything you need. I would choose FLAC if going for the best Audio Quality possible, as the Tags are easy with Mp3tag, and the compression of APE is not an excuse for lacking error checking and error robustness, which FLAC uses to make sure your lossless files are truly lossless. In a study over at HydrogenAudio, someone tried to play FLAC and APE that were both corrupted using a hex editor. The FLAC file had a second of silence, while the APE file refused to play at all. So really. Load it with FLAC and enjoy the sound. It is amazing with lossless and good headphones. The stock ones are complete crap, but everyone here probably has something $100+
 
Drag and Drop - Comes with software, but you don't need it at all. Just drag and drop. So easy, and you can keep your own folder system as an alternative to going by tags, as the S9 can navigate folders easily and quickly.
 
40 HOURS BATTERY LIFE!!!
 
Cons:
 
Tv-Out Cable is really cool with well-encoded Xvids, have watched a lot of movies at friends houses using this feature. Quality is limited only by the TV and the encoding. Great job on the cable, but it costs like $15 extra. Should be included in the package.
 
Line-in Cable is awesome too. Record any song from a friends DAP or a sound mixer or anything, but only at 256kbps WMA. Sounds great, but no WAV, sorry. Also costs extra, should be included in package.
 
Proprietary cable for USB and charging. Not a big deal, but Mini-usb would have been another pro.
 
UI: Easy when your used to it, takes about a week to get in the groove, after that your set. Also, Custom UI's from iaudiophile forums make your player infinitely customizable. I found a couple that work great with a bunch of user options and they look really cool too. One called "Dark Evolution" takes advantage of the S9's killer screen and displays album art as large as it can go. I tagged all my FLAC with mp3tag with 500x500 album art from Google Images, looks AMAZING. But I have to say, Ipods UI is the best. But you have to use their software and be another apple sheep. UI is definitely good, great if you consider the customizing options. I like it a lot better than the ipods' but I've seen people complain. All in all, if you have a little time on your hands to figure out and customize this bad boy, you will be totally happy with the results. I didn't get an anp because my headphones are IE8s and the ATH-M50, but you will want to if your connecting to a hard-to-drive headphone.
 
 
 
Conclusion
 
 
AMAZING. GET THIS NOW ITS ONLY $200
The new Itouch is $400 and doesn't sound or play video as well as the S9
The new Zune HD doesnt sound as good, or have as many sound tweaking options
The Sony X has noise canceling that messes with the sound that you have to use the bundled headphones with, an internet browser, you'l never use, inferior codec support and battery life, and far less sound customization.
 
This has no Line-out. So for you amp-loving people this might be a no-go. But if you use earphones or easy-to-drive headphones (I use ATH-M50 on Volume Level 10/40, and its completely loud enough) this should be your next purchase. Really, discount the haters. The UI is simple and intuitive once you get into it, and you won't have any problems unless you use a Mac, which is known to have problems with these. If you need more than 32gb (you probably don't, for portable use, just pick your favorite albums that you listen to the most) you can buy the Cowon J3, which is $100 more for an SD card slot and a crappy internal speaker. Anyway, I love it and use it everyday, and it completely meets my sound quality needs as well as others, enough that I use it at home with my M50s as well as portably with my IE8s.
 
I LOVE THIS PLAYER AND SO CAN YOU!