Just got the K167s delivered today. I'm definitely no audiophile as I've been perfectly content listening to streaming audio over a pair of twenty dollar Sony's for the past couple of years, but based on the dozen or so headphones I've listened to over the past couple of weeks, these definitely could sound better right out of the box. I've started the burn-in process with pink noise from simplynoise.com, so hopefully the sound will improve over the next 16-24 hours. If it doesn't, then I think these headphones are exposing issues in playback that others were masking.
For the price, the build quality could be better. The resistance on the right slider is a lot less than the left, so there's a tendency for the right side to collapse back into the headband as I stretch apart the cups to put them on (same problem alpha10 had). The headband is in three sections. The center section is made of a softer and somewhat flexible material, but the two outer sections are of hard plastic. The joints between the three sections do articulate. Isolation and earpad comfort is quite good and the level of clamping force means it doesn't feel like I'm wearing a set of vise grips. These will certainly stay put. I think the hinges will hold up with use because of the way the cups rotate while wearing therm, provided they aren't stretched too much while putting them on and off.
Anyway, so far so good and I can't wait to see what the next couple of days will bring.