It Lags for one, Its doesn't have the new physics engine (Infinity Engine). Doesn't have very intelligent hosts like the console variants. But the only good thing it has is Graphics. But not worth paying for; I think you should give it a try but do not buy.
This game does have its flaws and minor glitches that may cause you to call a timeout to fix. But that only happened once to me. Overall I think its a great football game. Good graphics and smooth game play.
It's no secret, the Madden series has struggled to perform ever since it became the only NFL game on the market. Considering the Vita version is essentially a slightly stripped down port of an already problematic game, it was fighting an uphill battle from the get go. All the things that has plagued the series through Madden 12 are here. Once you get over the, hey this is pretty cool I'm playing Madden on a mini Playstation feeling, reality sets in and you realize the game just isn't very good.