Made the mistake of getting GTAIII, and personally, I couldn't reconcile the controls. But that's me. Obviously a lot of folks loved it, but I figure if I didn't care for those controls, it's likely MP won't be much better. I used my credits for Amoebattle and couldn't be happier. Now, that's a game that really works for iOS. Takes up only a fraction of the space, has a Nintendo level of polish, and it's a blast to play.
Max Payne plays much better than GTA3. I can only play GTA3 in short bursts before getting frustrated with the controls and shooting mechanics.
Max Payne on the other hand plays like I wish GTA3 would. You can actually play the game.