Didnt know where else to ask - Iphone SF n Marvel questions

So Im finally giving in and getting an iphone. I know you can download SF4 and other games to play on the go and im definitely gonna grab a fighter or two right off the bat but im wondering-

Whats the difference between SF4 and SF4 volt?
Whats the rosters like in SF4/SFxT/MarvelvsCap2?
Are there trials or anything of that nature in any of them?
Can I fight other people just using my wifi connection or do I need to buy other stuff like a blue tooth or whatever?
Are any of these games even any good on mobile?
Are there any other quality fighters besides the 3 I mentioned?

Thanks in advance

“Are there any other quality fighters besides the 3 I mentioned?”

KOF 13 I suppose

http://cyberfanatix.com/2011/07/06/the-king-of-fighters-xiii-for-iphone/

No, they’re not as good as console. SF4 doesn’t even use 6 attack buttons, and I think it uses a 1 button throw system.

I mean, it’s more fun than Angry Birds…

SFVolt is not SF4. It has similar movements and characters, but you will be able to transfer close to zero knowledge outside of super basics like “don’t jump” and “ryu throws fireballs”. It’s a touch screen game with hackneyed controls. Don’t spend a lot of money on it.