I thought he had a good game too. Allegri is harping on him defensively but honestly he is better defensively than anything I ever expected.
Is he Mandzukic or Cuadrado? No, but is that what Allegri is expecting? That's a bit harsh. Against Samp though, he was tracking all the way to the goalline and he put in a couple hard sliding challenges. That's already better than 75% of wingers.
Offensively he lacks a bit of that cunning, sly trickery that all world class wingers have. Where they change pace and have their head all the way up. He's more one speed with his head down.
He seems to have a script playing in his head for what body feints to make when he gets in certain areas. I'd rather he stop with double step-overs and just play with his head up. If a defender comes in, he can easily just touch past him and hold him off with his strength. Make the defender make the first move, in Italy that's crucial.
This is how Higuain skips past people in midfield even though it seems he's nursing a child. He holds the ball out there but he can react to a quick challenge and just touch it past and then put his arm into you. Rarely do you see a step over. Same thing with Tevez.
With his finishing, I've seen he has the right idea almost every time, which gives me hope. They are mostly low shots aimed at the corner, not really Cuadrado style spray and pray efforts.