I put 3.0 firmware. There are some issues which make me to go back to 2.1:
- gain and balance were removed from DAC mode menu - i need them
- UI looks nicer but it's less intuitive and more complicated, you have to press multiple times to do same actions - reach music settings, increase volume, bass, treble, and so on
- long press on back (upper-left) button brings up a circular menu hard to browse, the 3 horizontal lines option does nothing, goes back to play screen, changing play mode works but also goes back to play screen; so to go to next play mode you have to bring up circular menu again; this is easily done in play settings but circular menu is called "quick", is not in this case
- list type menu is easier to browse then 2x3 grid - with diagonal buttons, focus has to go right, down, right, down; when changing e.g. volume level, they control a circular progress "bar" - so they do same stuff (up-down control) in different manners which is not too consistent.
- song title, artist and freq/bit rate disappear from play screen after 2-3 seconds - this might be set up somewhere but i don't know where
- i think i like more sound signature on 2.1 firmware (not that quality is lower in 3.0) - this and first point are the most important
Anyway, i like x3, i also use it to listen on big speakers thus avoiding space waste of cd players or pc/laptop.
Question (maybe it was discussed): is there any chance to make x3 work as amp for android devices using otg cables? thanks.