So ordered the m80s yesterday and chose 1 day shipping for $4 from amazon. Here are my first impressions.
I plugged them in and put them on and was instantly disappointed as i could hear tons of static/hissing. Later i found that this sound was present while they were completely unplugged. It is just a resonance from the headphones themselves, sort of a seashell effect.
Started playing some tunes and was mildly pleased with the unamped sound being pushed by my galaxy nexus. Though they don't feel as well balanced as people say they are. The bass is definitely not overpowering at all as some people say. Definitely need some burn in. I would not say these are noise cancelling at all though. Had some background music that someone was listening to so i had a good judgement of this. It felt like the background music was amplified if anything.
Being new, i didn't know the difference of on ear. I guess i like my big poofy cans all too much. As these seem way too small and stiff. I cannot get them positioned on my head just how i like.
Given all that, i still really like these, I'm just not sure what about them i like so much.
EDIT: second thoughts after reading through this thread.
About clamping force, mine seem extremely loose. I come from a pair of Beyerdynamic DT990 Pro 250ohm, so not sure if this is a contributing factor. Perfect set of cans would be a bit looser than these DT990s, but they are close to where I would want already. The M80s are uncomfortably loose. Not sure how one would consider them active headphones for workouts, I am concerned them may fall off if I bend over to pick up a dollar on the sidewalk.
Also, about size, i had to fully extend these to get them to fit right. I could only imagine what it is like for some one with a bigger head than I.
Edited by Spillages - 1/3/13 at 6:06pm