anyone here have any experience with R&D power valves in the GPr?
do they give that much of a gain in power?
are they worth the cost?
basically; are they what there cracked up to be, or just as well with stock?

I'm in the process of building a 800r motor and am currently waiting on these power valves as there on back order(6/8 weeks) just wondering weather to wait or buy stock and finish my build.

Thanks for input,