OK, I have a JP1 and a JP3 that I run on my RB WS7II, the 1 has a ton of bottom-end but gives up some on the top. The JP3 gives up just a very little bit of the bottom but out pulls the JP1 on the top by a mile, I like the JP3 better all the way around, on tight loose tracks it reduces wheel spin coming out of tight turns and on larger tracks it rocks! I don't even use my JP1 anymore