The phone version of MI2 doesn't have iMUSE. That's a deal breaker for me. Most of the time I'm on the phone, it's either a text-based game or a book. Batteries die quickly when you play games (of course, the Internet kills batteries too). I don't disagree about convenience, though if I know in advance I'll be traveling or having down time, I'll bring a dedicated device like a kindle (or my 3DS in theory, though I've never played anywhere but home). Missa ab iPhona mea est.