Akg k271 mkii? what you think?

The K271's definitely fit your musical preferences. They are really great for acoustic music.

For isolating, however, they don't isolate that well. I've never been on a train, so I don't know how loud they are, but I can't imagine them being too quiet. The K271's only block out certain noises well, like low-volume voices, so I can't see them being great for train use.

I've heard lots of folks say the Sennheiser HD25-1 II's block out sound really nicely, and can be found for about $200.

I own the 271's, and I think they're a great headphone.  They are very versatile, (They sound great with a surprising number of different genres.) they sound pretty good unamped, as long as you're willing to turn your ipod up to near full volume to get to a normal listening level, and they really come into their own when hooked up to a decent amp. (I use them with a NuForce Icon HDP in my dorm)  In answer to your question, sonically yes, I think they're a great choice.  However, I personally wouldn't where them on the train on a daily basis.  Generally, I close the door to my room before putting them on my head for fear of ridicule.  They have a robust construction, so you need not worry about breaking them, as long as you're careful.  Actually, I am in a similar position. I'm looking for a pair to wear back and forth to class.  (something that has a slightly smaller form factor, and something that I wouldn't be too embarrassed to be seen in public wearing,  the AKG's are BIG headphones mind you)  The Ultrasone Pro 550's caught my eye.  I've heard good things about them in the past, they have a new color scheme this year which is fairly attractive, in my opinion, and they can be had on Amazon for $150. 

I think the Ultrasone's are a great option for portable use. They are pretty nice looking, nothing too crazy, and, particularly the lower end models, have very well rounded sound. Wasn't a big fan of the higher end models, as the highs were really grating, but the 580's I listened to had very smooth highs and mids, really not recessed at all. I didn't get a chance to use them in a noisy place, but I'd imagine they isolate very well, since the cups are metal.

Another option is the Sony MDR-V6's. They are lower profile than the K271's, still a little bulky though, but isolate very, very well. People say they have pretty aggressive highs, but I still found them to be more pleasant than the higher end Ultrasones.

Yes, AKG K271 is THAT big. As big as your head. You'll look like you're wearing studio equipment, which you are. But looking like you're wearing studio equipment when you're not in a studio or doing production activities make you look like a goof.

Even the relatively large Ultrasone PRO 550 will look much better in public, assuming you know how to dress up to match those gaudy blue headphones haha

PS: Forgot to say that the K271 are exceptional headphones. They will sound great with your music. haha

Yeah, the K271's really lack bass. They extend low, but with very soft bass.

The HD25-1 II's are a lot smaller, and they do have bass, though they may not pair as well with your music as the K271's.

It's more like the K271 has boosted mids and a bit honky, or rolled off on both ends.  It has good extension, but the mids are overly dominant.  I've got a pair, definitely one of my least favorite headphones.  I use it to change up the pace now and then for my office rig (need isolation).  I don't care for them at home.

I'd look at the ATH-M50, in that price range, if you really want a full sized headphone.  It offers a more rounded sound.  Otherwise, you can check out some IEMs which isolate much much better.

I wouldn't say the HD-25 doesn't suit your musical tastes, rather the K271 is very limited in it's capabilities due to it's mid-range focus.

I never heard of a headphone lacking versatility due to mid range focus... Rather, the opposite. The mids is where all the music is. Either way, even having said that, the K271 lacks too much bass for some people. I loved it for the most part. Excellent clarity, but I just craved more bass and volume. I had difficulty driving them with a portable amplifier.

It's not the end of the world, Audio Technicas can do your genres very well.The ESW9 or ESW9A would be perfect for you. They are extremely portable and sound optimal with your music.

Maybe I should clarify, I didn't mean to say the HD25-1 II's would be bad for your taste in music, just they wouldn't match as well as the K271's. Acoustic and K271, K271 and acoustic, they're like two peas in a pod.

I just had 5 new headphones at home, from which I chose the K271 to keep. I think they're great, but I would never use them during traveling. I have nice IEMs for that. If you really want something on your head, the HD25 is much smaller than the K271, but it's an on-ear design. The M50 is also very good, but that one is already as big as the K271.

Are you sure you don't want IEMs? I have the Etymotic HF2 with my iPhone, they're small, light, very well sounding, and maybe the best part - they isolate extremely well. If you play music through them you will hear absolutely nothing from the outside world. My friends didn't believe me at first, then they started yelling full power, but I really couldn't hear them.

That being said, the K271 sound better and offer also pretty good isolation (especially compared to other closed full-sized headphones), but like I said - I think they are too big.