Pros: Amazing sound, sounds alright even out of poor sources, great case comes with headphones, great isolation, very handsome and sturdy
Cons: Not many user replacable parts, a little pricey, uncomfortable for long listening sessions, some design/aesthetic flaws, very finicky
I couldn't believe my ears the first time I heard the DT1350. It seriously blew me away. I was expecting it to sound pretty good, given all of the positive reception it has been receiving here and elsewhere, but Jesus. I wasn't expecting it to sound *this good. * In fact, I was so awestruck by it that I even thought it might be better than my full-sizes. (It's not, as I later confirmed--though it played a lot nicer with my jazz collection than my Denon AHD2000, to my ears. Mingus's The Black Saint and the Sinner Lady was simply beautiful on the DT1350.)
-The sound. I've listened to the Sennheiser HD 25-1 II, which many people seem to agree is the best sounding on-ear sealed portable headphone in production. And they are certainly very good headphones, there's no denying that. I think these are significantly better, however. The bass is more finely controlled (but still deep and heady enough to feel positively seismic at times), the sound stage is wider, the instrument separation is clearer, and all the little hidden details from your favorite tracks are easier to pick out. Other people are far better at describing a headphone's sound signature than I am, so I'll leave the rest to them. Suffice to say, I'm very impressed with the way these headphones perform.
-The DT 1350 does respond very well to amping, I've found--but even plugged straight into my 4-year old iPod Touch they maintain a lot of their positive sonic character. (Update: that said, they do sound quite a bit better amped--I'm not sure that I'd recommend these headphones unless you have an amp to power them, but they'll still do the trick without one.)
-These are very portable. Whether folded flat around your neck or traveling with you in the supplied carrying case, the DT 1350 can pretty much go with you everywhere that you need to go.
-Speaking of the case, it's pretty nice. I use it to not only hold the headphones, but also various adapters, interconnects, and even a couple of hex wrenches. You know--stuff you need everyday. ^^
-They isolate extremely well. If you're like me and earbuds and IEMs cause you physical pain and discomfort, but wish there was a headphone out there that approached their ability to isolate, you're in luck.
-Very attractive design. Probably not to everyone's taste, but I find them to be a real joy to hold and look at every time I take them out for use, aside from a few issues I raise below.
-The split headband is nice--I've never worn a headphone that was easier to keep in place than the DT1350.
-So far as I can tell, the only things that are easily replaced by users are the ear pads. In this regard, I wish Beyerdynamic had paid more attention to the design of the HD 25-1 II.
-Kinda sorta pricey. Do your research first before taking the plunge on these.
-They're not the most comfortable cans in the world. Not that anyone in their right mind would expect them to be... But boy, if you get overzealous about listening to them, you're really gonna pay the price for it later when you have to pry these things off your aching skull. The clamping force on these is seriously pretty intense--which no doubt helps with the isolation and whatnot, but ouch. I recommend not wearing them for much longer than 2 hours--4 absolute max, unless you're made of far sterner stuff than I am. (Update: the comfort is considerably better after these break in--or after your head breaks in.)
-While I like the overall design and aesthetics of these headphones, I do have a few niggles with them:
-If you're not careful when swiveling the ear pads flat, you can catch the cord right where it enters the cups between the metal bales (think that's the right term) and the metal band that holds the adjustment sliders. If you did this particularly forcefully and repeatedly over a period of time without realizing it, I imagine that this would not be a good thing.
-The plastic sheaths on the split headband look and feel rather cheap.
-The pleather padding on the underside of the headband is not convincing. Not only do the two strips of pleather seem to be off center on my pair, but they also seem to be unevenly and under-stuffed. The overall effect of the headband is a tad bit on the sloppy side. (Update: One of these crummy pads came nearly completely off on my pair after about 4 and a half months of semi-regular use--so not only are the pads themselves of poor quality, but it would seem that the adhesive that holds them onto the band is sub-par, as well. Obviously, it wasn't anything that a little bit of firm glue couldn't fix, but still, I was pretty annoyed.)
-Finding the sweet spot for these headphones can be a real challenge. Even if you have no troubles finding it once, you may be hard pressed to find it the next time you put them on. And even once you do have them on and have them sounding great, if you're at all like me, you're gonna be constantly readjusting and poking and proding them trying to see if you can make them sound even better. In my experience, the bass is the easiest to recognize aspect of the DT 1350's sound that is affected by how close you are to the sweetspot. Close but not quite and it sounds pretty flabby. Too far away and it's painfully anemic.
-This applies to folks with long, wavy/curly hair only. These will pull on your hair. They will pull your hair out. They will get stuck in your hair. If someone is trying to talk to you and you're trying to take the headphones off so that you can listen to them without seeming rude but you're doing it too fast, they will get caught in your hair and make you look like a complete doofus. You will seriously be standing there with these headphones tangled up and hanging in your glorious mane of hair with someone laughing at you and offering to fetch you a pair of scissors. The key? Remove them slowly, extending the headband as you go.
-The cable makes a lot of noise when it rubs against other objects. Pretty lame for a portable pair of headphones.
The DT 1350s are a pretty finicky and occasionally painful little pair of cans that sometimes make you want to hate them. But then they slip into their sweetspot and they're positively magical, and all is right with the world, for at least a little while. There may be other portable sealed headphones out there that will match your needs and price range better than these will--so, as always, do your homework first. And take into serious consideration the problems that people are bringing up with these headphones. I think they're worth it--you may not think the same.
(Update: Lowered the overall score a little bit and tweaked the other scores to make room for my frustration with the headband pads--read above.)
(Update: It seems to be pretty universally accepted that Beyerdynamic has been having some quality control issues with these headphones--if you get a pair that sounds like it should it's awesome: but it would seem that there are some pairs out there that sound and measure terribly.)