I probably sound like a broken record, as I've said what I'm about to say multiple times before. However....
Josh's presence is like the Tasmanian Devil: he's a strong force, but he can hurt you as much as he can help you. As of now, he earns his money almost strictly by uncanny athleticism. He's not a high basketball IQ guy, and I'd be very concerned with how well he can learn the game. He'll definitely make some huge plays for you, but he's lack of discipline and understanding of the game will give those points back to the other team.
As far as a PF goes, he seems like the kind of guy built for the regular season, when on any given night you can outgun the other team. He causes some match up problems and is explosive. However, he's not a half court PF by any stretch of the imagination, unless he's learned some post skills in the last few months. As such, he's not the kind of PF you want in the playoffs, where you have to grind it out and play smart. The best teams are simply too disciplined to let sheer explosiveness beat them, which is why Phoenix and Golden State didn't make it to the finals. (Well, that and an iffy NBA ruling on players staying on the bench.)
I'm not interested in him unless:
1. He plays SF for us, only occasionally playing PF when we play teams like Phoenix.
2. We get our act together so he comes into an established system. He puts too many variables into a system to make it safely work. I'd rather have something established and then bring a guy like him in. Although, obviously, that doesn't fit the current situation.
He's certainly high risk/high reward. But, unless you're playing fantasy basketball, I'd pass.