Yeah Rainsports are awesome. Driving Laura's car in the wet it still feels completely planted, it's like there's no water on the road. I'm sure if you pushed it hard enough they'd let go, but I find that driving at my normal pace there's no noticeable loss in grip with the Rainsports in the wet.
Rainsport 3's on my 5th gen as well. They deal with just about anything you throw at them. I have Rainsport 2's as my wet set of wheels for the 4th gen.
I have Federal 595 RSR semi slicks on my 4th gen and in the dry, on the road, I cant tell the Rainsport's and Federal's apart in terms of grip as I don't get near to either of their limits.