I just bought a new Cross Roads last week. I test drove one without the RPW's, and one with. I was told the power difference was somewhere in the area of 5%, however I dont buy it. It felt like more than that. I drove the demos a couple more times to feel the power difference, and its very noticable.
I immediately said put the RPW's on the new scoot, no doubt about it, it was a no brainer.
They just do a stage 1 reflash, and put on the RPW's, and off you go.