Concerning v0.15:
Issue resolved:
1. Artists/albums categories don't repeatedly update once device is powered off/on
Issues unresolved:
1. Once out of the 'now playing' screen, cannot stop/pause; moreover, no way of returning to the 'now playing' screen. In order to stop/pause a song, had to press the forward button to any new song file. (v0.14 was able to return to the 'now playing screen' by pressing the back ['< ']arrow button.)
2. 24 bit files still not working without first playing a 16 bit one. (This is a non-issue for me, as I hardly use 24 bit songs.)
I have reverted back to v0.14, as I can live with the albums/artists updating in v0.14, but the device becomes absolutely unbearable with the stop/pause issue. For reference, Kingston 32gb class 4 used.
As always, sound quality remains a gem.

(Oh, by the way, shouldn't this update go in the firmware thread?)