I don't think I'd like the GBM because my hands are big and they'd be cramped. Also, it's basically the DS without the DS's capabilities. By that I mean you can't play GB games (the only reason I kept my GBA). Sure, it still does multiplayer, but you need to get a special cord, then an adapter thing if you want to connect to an older GBA. Size doesn't really matter to me, since I'm always carrying my games around with me anyway, so a GameBoy the size of a Nintendo 64 probably wouldn't even bother me.