I bought the Hd 212s a couple of weeks ago and have been listening to them almost nonstop since. i have most definitely achieved burn in. as these are my first 'good' pair of headphones i am kind of hesitant to write a review as i have nothing to compare them with. however i do know good sound as i have a fairly expensive sound system on my computer and a nice system at home too. i know this does not directly correlate to how phones sound, hence the no review yet....
well, i listen to the 212s on my portable and on my computer
(no amp in both cases) when i din't want to disturb my roommates (i'm in college) and they work fine in this regard. they leak very little to no sound. i was blasting techno almost full volume on my portable and noone could hear, but that was on my portable. if i turn the volume full up on my computer then the phones can work as a sort of mini speakers...i can keep them several feet away and listen to the music comfortably wiht no distortion of any sort. so they can be very loud too.
bass is fine...not TOO loud, but loud enough definitely, and let me tell you, i like my bass. and if you want headache level bass you can always use the bass boost.
so i think for someone with a limited budget ( about $50 or so, and no amp and sealed headphones, which was exactly my case), the 212 is the best choice. i thought about the 280s, but they were too expnsive and they also look kind of big and nerdy.
and that's my two cents. if some of you really want me to write a review then i will, but i like i said i don't have too much to compare it to, so...