Just got a pair yesterday after hearing about them on head-fi, and doing a little research. I have to say, they've taken a little time for me to get used to, as my main desktop pair of headphones right now is a set of Ultrasone Pro 750s which have extremely pronounced (read painful) treble. The Zoros, on the other hand, definitely have some roll-off in the treble which causes them to lack a little sparkle, but at the same time makes a lot of the electronic pop music I listen to infinitely more enjoyable to listen to than it is on the Ultrasones, as the high-pitched chirps and beeps are much smoother and less sibilant.
Mids seem slightly recessed, causing vocals to get lost a bit in more complicated tracks, but for the most part they sound quite good.
The low-end is where these really impress me, as the bass is tight, punchy, and surprisingly deep. Silent Shout by The Knife (which is my go-to track for testing bass thump) sounds almost as good on the Zoros as it does on my Ultrasones, which is impressive, since the bass was the main reason I settled on the 750s in the first place.
All in all, these are certainly the best $50 headphones I've ever heard, and -as much as I hate to admit it- I think they might sound more pleasing to my ears than my $250 Ultrasones. Not that they're better, mind you, as the Ultrasones are far more detailed, but the Zoros have a more balanced sound and far less sibilance.