The only issue I have with SFxT is that they didn't add the complete roster for both series. Besides that, it's fun I just started it. I think its kinda cheap because of the gems deal. I don't like megamans look. (i know why its like that but i dont like it)
I don't really know what the difference is between SS4 and the Arcade Edition, but I suggest the Arcade Edition from those two.
UMvC3, not very fair. If you know the combos then as long as you get the first hit, youll win.