Between A Radeon DDR and a Geforce MX, I would definately recommend the Radeon. It just looks so good, hard to imagine playing without it now. As far as comparing it to the GTS2, the GTS 2 is much faster. I haven't seen a GTS 2 in action, So I can't really say. No problems with install or any compatibilities yet.
Graphics are outstanding.
I never knew games had so much detail in them. Colors are vibrant, textures are complex and gorgeous. I'm very impressed so far.