Pros: Fairly balanced sound, not too dark, clear sounding
This won't be an in depth review, just a few short impressions. Scored these for $90 at Radioshack. I always wanted to try a V-Moda headphone that wasn't too bass heavy.
Since all my portable players were dead I used my O2+Modi (transparent IMO). The low mids were shoved in my bass and these were too bassy. Well guess what? The cause was my powered USB hub crapping up the sound and with the amp/dac and these headphones I was able to detect it. Problem fixed!
They have a slight mid-bass emphasis and I was surprised that the low bass extension is very good. The mids are no longer shoved in my face. These actually don't sound dark at all and managed to have very smooth treble.
None of my music seemed colored. The sound was pretty crystal clear too. With most headphones under $150 or so they can often sound fairly muffled or too dark. I actually had just returned an HD-380 and these sound WAY more balanced. I couldn't detect any recession in the mids at all.
Unfortunately the deal killer for me is that they were painful to wear. It seems like the design is incompatible with my head. I don't have a horse shaped head or one that's too big. I had to fully expand the headband. They hurt the tips of my ears and feel like a giant claw is grabbing at my head and trying to pull up. I think it's due to the Beyerdynamic style of metal headband. I did try to stretch them out over night but couldn't even take 10 minutes of them. I guess i'm the rare exception.
I hope V-Moda reads this because I'd really love a neutral sounding M80 that's over ear. I think the M100 has way too much bass for me probably.
So overall, loved the sound quality but hated the comfort. Ended up returning them. Kind of hard to do.
I still think the DJ100 with M50 pads sounds better but those are too hard to drive and too picky with gear.
M80 actually sounds more balanced than the SRH-840, K240, M50 and definitely the KRK KNS-8400/6400. The low bass is as extended and as present as the DJ100 and KRK KNS-8400. My DJ100 has a little more treble, more forward upper mids and maybe a tiny bit less bass.
Almost forgot..the soundstage with the O2+Modi was actually pretty impressive for such a tiny headphone.
NOTE: The audio quality rating is for closed headphones in the $100-$200 price range. I'd say they're comparable in sound to the M50, KRKs, SRH-840/940, DJ100, K240 Studio and a few others. Obviously they all have different signatures.