see what happens ...

1) On firmware 2.8 - works most of the "watchface" but sometimes you have to install them with Android devices, since "Rockwatch" can not set them back
And also, on firmware 2.8 does not always work correctly control your music player

2) on firmware 2.4 - normally works to control your music player. installed many "watchface" through "Rockwatch", but not all!
and not all applications can be put even through Android device (need a newer version - 2.8)

3) if the firmware 1.14.0 it - works great player controls.
* well installed "watchface" through "Rockwatch"
but very little of interest "face" on this firmware

in the end I chose a version 2.4

ps - sory for bad english