I like the banshee shock better personally. The 660 might be a little better performing, but I didn't like it because it lifted the rear of the quad too high and messed with the chain geometry, I sold it and went to a banshee rear and liked it better. I can't speak much about the performance of the banshee because mine was a completely aftermarket shock from WP, but it fit much nicer than the raptor shock and was easier to adjust. You will have to modify the airbox a little if you go with the banshee shock though, the piggyback reservoir needs a little extra clearance which can be achieved by heating up the plastic with a heat gun and pushing a dent into it.