I was at Stereo today to demo the K10 and I found it a bit underwhelming, at least compared to my Fitear TG334. Not trying to haolian/fanboy here or anything, just honest comments. I've been wanting to see if K10 is a superior upgrade over the TG334 for a while now.
The K10 is very coherent and well-tuned, it's like having a setup with great synergy except it was just iPhone/ALAC > K10. Very natural sync and decay, and you can feel the instruments "let go (放)" and "retract (收)", to use the terminology of those singing competitions.
The nuance is there and you are listening to the song as a whole (rather than vocal-forward etc).
However, the TG334 wins out by a huge margin for me in terms of clarity, excitement, highs and lows. IMO the K10 fares very badly with electric guitars and the bass isn't deep nor punchy at all, in fact I would take the UM Merlin before the K10 for general/pop genres and only K10 if it's towards the acoustic/ballad/instrumental side.
Of course, it could be that the iPhone does no justice to the K10 but nowadays I think people don't really carry stacks around and the Fitear does remarkably well straight out of the iPhone.
The good news, for me at least, is that I'm quite happy with the TG334 as end-game and don't have to worry about K10 anymore
P.S. Maybe the demo unit is spoilt, I have no idea of knowing. Someone should go check it out, lest I ruin the K10's reputation.