I'm just going by what I've read. I actually have a laptop with a GTX570m and I can't complain at all.
I'm still a big proponent of software matters more than hardware. That's why I still think nvidia is the way to go if you're a "huge" gamer on a phone. The tegrazone stuff really does look fantastic.
For the tegrazone stuff I can just use chainfire 3d. Same thing after that.