only issue I had is with the bundled soundpacks,
Obviously these are not the same from Studio or producer edition,
so when you uninstall Studio, it erases that soundpack too,
and installing PE over does not put the same sounds.
So I did lose some oneshots and loops from the bundled library for quite a bunch of songs.
not ones that are in the project itself (but ones that were in 3rd party sample players or stuff like that).
But opening projects done on Studio onto PE works just fine.
I hope that helps !
Cheers !
V