Hello,
For me:
1) OS3.9 - BB1 on my A2000 (my A2000 doesn't boot when I install BB2, maybe due to a ROM remapping problem) and OS3.1 on my A1200
2) OS3.9 looks nice and includes CDRom features, transparent menus, and so on... OS3.1 is just enough for my game-oriented A1200 (boots very fast !)
3) I don't want to change !
Alma96