That bolded bit is exactly it. The whole thing really. He was a very soft player back at the start of the season. And only seemed to have eyes for goal... then a little later, switched to just passing all the time... but since the winter break he's been absolutely immense for us, physically stronger, tougher, stays on his feet more, finishes better, passes better, is more aware of his situation, he does everything better.
He has tons of room for improvement in all aspects, the biggest probably being looking up more often with the ball at his feet when he's near the opponents goal... but even that has been improving, and there's no reason to think he won't continue improving month by month.
Alvaro is going to be a star. I just hope it's here, for Juventus.