I collected my UM3X in Singapore last Friday. First impression, WoW!, the bass. Plenty of it. Mids/vocal sound bigger and a bit laid back compared to PFEs. Treble is good too, but PFEs' slightly win. Totally different sound signature. But, the best thing is, it is very easy to drive, and make DAP sound much-much more better, even the cheap DAP also sound great. Imagine, if you use it with a better DAP, such as iTouch 2G and Sony X1000s.
But, the differences between DAP sound and DAC/AMP (D10) is, the bass and treble extensions, resolution/details, separation, and headstage. Since I am not audiophile, I am not care much of it

heh he he, and still prefers D10.
Now, I really have to burn-in my mental to the new sound signature.
Ooo.. I also tried the IE8s briefly. I had plenty of bass too, but, not as controlled as UM3X's. Will do a serious listening ... and post some more here

BTW, I had returned my PFEs for replacement, and luckily, I got the UM3X to satisfy my ears during the PFE's absent.
Thank you.