The knock on him has been his speed. However footy takes all types and there's been plenty of great players without leg speed (Greg Williams is the first that comes to mind). But to be a great player in that context, you have to have other attributes.
I remember watching Graham at VFL level when he first started and the two things that stood out was his big body presence and tackling in contests (he seemed to enjoy contact and not all players do) and he accumulated possessions. At AFL level up to now and when his body is right, he's been good at the contest but hasn't got enough of the ball. He's now started to show signs of the latter.
His pressure acts are gold and that clears the way for the other midfielders, but to cement his place he had to find more of it and use it. Now his body is right, he looks like the talented youngster I first saw at Punt Road. I'll also accept lack of pace if he can run all day.