I think I'd give him about 5 out of 10. But it's hard to say, because I generally despise his players. Also, this is (obviously) very subjective.
(1) I think he does a pretty good job on pacing, which is important for GMs.
(2) I don't find his game sessions to have any real depth... but then again, in his public videos he's only got a couple hours to work with, and he wants to keep the story moving.
(3) I hate that he uses different voices, as it pulls me out of immersion, but I understand that many people prefer that.
(4) I don't like that he "says yes" as much as he does (not that I'm against "saying yes" being done), but that's also personal preference in a fantasy game.
(5) It looks like he adapts pretty easily (at one point I'm fairly certain he turned some standard minotaurs into minions because they were low on time). That's a plus.
(6) His advice on GMing (in his old column) was alright, but nothing ever struck me. I couldn't list any of his advice now. I will say that it made his off-camera campaigns sound as if they had more depth, which goes against an earlier critique of mine. I just can't be sure one way or another.
Regardless, he seems like an amazingly nice, gentle guy during panels and stuff he's involved in. I don't know much about him personally, but I don't have anything against him. If I could somehow get passed the voices and end up in a surprisingly deep game run by him, I'd move my assessment higher. But, based on the public videos, I'm keeping it at 5/10 for now. Again, though, I might be biased by hating most of his players.