Before I get into the gory details, I have to start with saying that I bought these refurbished for $34 on amazon, which is an absolute steal(boosting up my Value rating). If you can get them before they're out of stock, absolutely grab a pair. Now then, onto the good stuff.
The Look: I personally love the styling of the Vmoda Crossfade line of headphones over almost all others, but the minimalistic look Audio Technica uses I think is beautiful and not all up in your grill with branding like some other headphones. Matte Black with silver accents, making for a finger print free headphone. Brilliant.
The Build: The headphones feel really light for what is claimed to be inside of them. I don't think I'll personally have an issue with the build, but that's because I'm not taking these out unless I go to a LAN party, but if you plan an using these for mobile, be weary of the all plastic design. It has a small leather headband on top, which on most headphones wouldn't be acceptable, but these headphones weight is entirely on your ears.
Comfort: If these cans have one fatal flaw, it's the comfort. It's an on-ear design, with an over-the-ear style cup. I can imagine that doing it like that improved the sound quality because you're ears are further from the drivers. The clamp force is quite heavy on these as well, making them even less comfortable. Yay! Joking aside, the clamp makes it so that when you thrash these headphones around on your head, they won't fall off. All this adds up to not being able to wear the headphones for a long period of time, which is disappointing considering the sound.
The Sound: Now what you all came here to read, the sound quality.
The Bad News: As I stated in the cons, the highs are painful. When I tried these on my HTC OneVX for the first time, the highs almost made my ears bleed. I thought the highs in my Crossfade Lps were harsh, but these brought it to a whole new level of pain. Listening to The entire Pax Vesania album by Yōsei Teikoku murdered my eardrums. As far as using these as mobile headphones, it's an absolute no. Hooking these up to my computer lead to other issues. While this may not be an issue to many listeners, I like to listen to my music loud, and that's impossible on these cans. It's not that they can't get loud enough, but they distort over 60% on my volume slider.
The Good News: Even though the sound is unbearable on a mobile device, there is a light shining in the darkness: equalization! Simply decreasing the 500hz / 8k / 16k frequencies made these things sound fantastic simply on my MSI motherboard's on-board audio. The bass wasn't as overpowering as I thought it was going to be. Often "x" bass mode or level is a buzzword for horrible sound quality in cheaper headphones, but the WS55s don't disappoint. While the bass isn't as deep or fill the entire track with a lovely underlying low notes as the Crossfades, the bass is certainly there, and doesn't leak into any other parts of the track.
Now you may be asking yourself "Why, what genres do these headphones excel in, good sir?". Keep your pants on, I'm getting to it.
I mostly listen to Metal and various genres of EDM, and in one of these two, the W55s excel. Sadly, Metal isn't the one. While some bands like Protest the Hero and Coheed and Cambria do sound decent, more bass-oriented metal like Yosei isn't enjoyable. Without the lower end of the bass notes, the tracks lack the umf that can be doled out by other bass-centric headphones. "Curses!" you scream to your monitor as you shake your fist in rage. Hold your horses, I haven't gotten to EDM yet. This is where these headphones excel over deeper bass headphones. With the fast pace of Glitch Hop and other faster BPM genres, these headphones can keep up and reproduce the tracks with immaculate detail. Highs and trebles fit right into place on almost all tracks.
The Bottom Line: These headphones are amazing for the price. Compared to my $200 Crossfades, they kick their ass for at-home listening, but get wrecked in mobile applications. They need to be EQ'd and will be seen as uncomfortable to almost all, but they're worth a listen.
Edit 30/12/2013
After listening to AKG K550 Reference headphones...extensively...I've gone back to these headphones to see if I still agree with what I stated before. On the comfort side, they haven't gotten any better, obviously. Durability wise, I've brought them back and forth to class daily since I got them with no issues whatsoever. Even pulling rather hard on the cables when standing up from tying my shoes never caused a single issue. They are quite good for mobile use, as the terrible Beats Audio EQ on my phone doesn't butcher the sound signature that these headphones boast, and their compactness means I can throw them even in my small laptop bag. Sound wise, my opinion varies a bit. On the bass side, I still like them very much. It's a nice change of scene from a more flat response when listening to EDM. Rap, no matter how seldom I listen to it, is also enjoyable with all that extra bump. Even thought there's a lot of bass, It's not as overpowering and distracting as in the Beats Solos. The other parts of their sound however, heh. Not what I once thought they were. Even while I only had these headphones, I never really liked the way they treated other less bass-centric genres, and it hasn't changed one bit. Even when listening to music in FLAC, the tracks sound like the vocals and most of the highs sound like they were recorded on a toaster.
The REAL Bottom Line: I admire Audio Technica's dive into the bass-loving-consumer market for headphones with the WS line. It's providing a line of headphones for people who love bass to not be embarrassed by(Skullcrushers, Beats Line), or having to use incredibly large headphones to aquire that bass(Sony XB500/1k). If you listen to anything besides bass music, stay away from these headphones like the plague. However, if you enjoy cheap, on the go headphones with a load of clean bass, look no further then the Audio Technica WS55s.
Also they are quite comfy, but the biggest problem lies in bad mechanical design and selection of plastic material. They become squeaky as hell very fast. Slightest movement and you hear cracks and whines. So I took them apart and used their drivers in other headset. Successfully.