You cannot play mp3 files from internal drive, yes you can play internal styles preinstalled.
Also even after playlist converted, yamaha have told me I have to move all my files to the exact same position and tell the playlist where the songs are.
This will take hours.
1. I have no problems playing MP3 files from the User drive.
2. Yes, if you move your user files (styles, multipads, etc.) to the User drive, you need to update your registrations, but Murray Best's Registration Manager makes the process easy. It too me minutes, not "hours", to convert my 1438 registrations. And even if it did take "hours", what's that compared to a lifetime of enjoyment of the keyboard?
To me, there are lots of annoyances with the Genos, but the SSD User drive is not one of them. It's the keyboard's best feature, and well worth the time to take full advantage of it.
Fred