Short answer: I really don't know.
I'm not one of those folks who thinks he's automatically overrated. You hear so often his striking is non-existent, his takedowns suck, etc. but fight after fight, he's got his opponent on the ground. Far more often than not, he wins. Busting Hirota's arm in a little over two minutes while essentially not getting touched is pretty impressive to me.
My question is his size. I doubt he cuts much weight, if any. I'll be really excited to see him against Melendez, without tights, in a cage. I think that fight will answer a lot of questions about his current ranking.