'Good but not great' is an upgrade on a lot of the players we've had in midfield in the last few years.
I like him, he improved a lot as the season went on. Good range of passing, tenacious off the ball and skillful enough to make space for himself when he's closely marked. There is a lot of room for improvement but unlike some other players, I think he's capable of making those improvements over time.
Also helps that he has already adapted to the PL and worked with Arteta so he can pick up where he left off and hit the ground running, whereas other players might need to be bedded in.