Just recently got my X3 through the Adorama sale...
A few questions/observations:
1) Upgraded to the latest firmware after a few days. Started hearing the dreaded "popping" noise, mostly just before playback, almost always from startup. It's not created any problems with playback, but it is distressing nonetheless...
2) This thread is huge, but I've sampled posts here and there regarding file browsing. My only issue so far has been if I have artists with multiple albums, there is no way to browse by Artist and then by Album...you get every single track from every single album. Is there any workaround to this? Something to hope FiiO fixes in a firmware upgrade?
3) Some screen protector questions...one was on the player out of the box, 2 new in the box. There were a few air bubbles under the screen protector...I attempted to peel off the sticker, which wouldn't come off cleanly and left a ton of adhesive. Now the screen protector is nothing but air bubble pockets and cosmetically looks pretty bad. Any tips on putting on one of the new ones? Can you even find extras to buy if you need to? I found this listing and was wondering if anyone's tried these yet: http://xoskins.com/media-player-skin-protectors/fiio-screen-protectors/fiio-x3-screen-protector
4) This has only happened once, but...the player was idle and turned itself off. Wouldn't start up again until I plugged in the USB cord and began a charge. Should I have hit the reset button?
Other than those issues, have been enjoying the sound quality of all my 16/44, 24/96, and 24/192 FLAC files. Amplification is more than adequate for my Beyerdynamic DT1350s. I noticed a slight cyclic noise when I turned my amp all the way up when I tried it out as a DAC, but this didn't get in the way of the sound of files during playback at a lower volume.