Personally I think Perk pre-injury was the better player. I always felt like Perk was a better offensive player than he was given credit for. Not a good offensive player, mind you, just not the useless stiff that he is often accused of being.
That being said, GS has improved a ton this year, much more than I would have ever thought. If he continues to improve at this rate, he will definetely eclipse Perk. But few players are able to do that. It's a close call, but if I had to guess I'd say it's a no go.