He's done really well, to be fair. I'm not a huge fan, but he has adapted well and makes me shit my pants less these days than early last season when he played centre back. I think people over emphasise his football intelligence because of his physical limitations, though. Rio was, in my opinion, a much smarter defender. He knew when to drop back, when to press and when to just follow the player. He even knew when it was wiser to let the attacker get to the ball first (something at least one attacker said was very annoying as they thought they would have him beat, only for him to knick it in a much better position from a defensive point of view). Blind is a little bit all over the place at times. There is a reason why Bailly has do some of the sprints he has to make, and quite a few of them are down Blind's side - the same applied for Smalling last season. Whichever centre back plays alongside Blind, they have to do a fair bit of running.
His passing range does let us get away with a two man midfield to a much greater extent though. He is also good at intercepting, I think, especially between defense and midfield. He isn't the best in one on one situations though, but Smalling was a beast there last season, nor is Blind the tallest defender or makes up for it with a great leap, but that isn't such a concern now we have Pogba, Fellaini and Ibra in the team. Although I think he has done well, I would prefer to see a Smalling-Bailly combo in the middle. Attackers would simply stop running at our defense, just like they have stopped doing it against Valencia; why bother?