No, I don't think he is anywhere near as dirty as guys like Artest (and I am sure there are plenty of others who aren't as prominent).
The problem with KG isn't so much that he is dirty, but that he gets under peoples skin. He is much more talk than some of the real dirty guys, who may keep their mouths shut a little more, but whose actions are much more dispicable. I would argue that if KG kept his mouth shut, he wouldn't be seen by anyone as a dirty player.