I have had the M100 for like 2 days , but I will be happy to express my feelings about them to this point. Please look at my profile so you can see the different headphones I am accustomed too.
I have tried my Clip + and FiiO X3 as my audio source and mostly FLAC and 320kb files. I am using high gain and 0 tweaks in bass or treble.
Accessories: Great case(small, uses space wisely) durable, if you like kevlar cables then you will be happy
Build: Awesome build quality, designed well, feels heavy duty
Comfort: A little pressure, and one of my ears is a little sore but the same thing happened with the Momentums, no headband pressure, slight clamping
Sound: This is tough...yes bass, yes treble, mids distant(not covered by excessive bass, just recessed). I want to say if I miss something it is a bit of detail. There is some detail lacking compared to say my HP50. I write this knowing what these headphones are, more fun than precise. Sometimes I lose detailed parts and other times they are detailed. I have found that with very detailed music such as Dream Theater the sound appears all mixed together, not so defined, I think others confuse this to say muddy, but I don't think that would be correct. On the other end of the scale when listening to Talking Heads Burning Down the House and there are a couple of instruments, such as in the middle of the song when the drums solo, the drums and bass sound awesome, the keyboard a bit distant. YYz by Rush sounds incredible, but with a little more mid even better. Smells Like Teen Spirit has never sounded so powerful. Nirvana, In Bloom, sounds messy when all instruments are cranking but when it is the bass, drums and vocal part only, awesome. With jazz, it is also a mixed bag. I feel the M100 possibly excel a different genres but too me it is not so much genre specific as it is song specific. Some songs I hear and I am wow'ed other songs when the music is involved it is blended and more difficult to single out specific instruments. When it is the right song the instrument separation is just great. They are strong and powerful headphones.
I am hesitant to say anymore because I think I need more time. But here you go!
Thanks for the detailed response. The best I've heard (to me) have been the PSB M4U2's. if I could have the M-100's awesome build quality with the PSB sound (haven't heard the HP50) then I'd be completely happy. It's V-Moda's reputation and the great things I've read about the company and Val in particular that has me not completely giving up on them yet. That's why I'd like to audition the M-100's and the XS' as well in a more controlled environment. It could just be that their sound signature just is not for me...