We just put one on Juniors 02. It may have lost a tad off the very bottom but mid range and top is great. We have been running a Doma pipe and silencer. The V force at the hi tension settings woke this bike up. Junior is one big 13 year old, 5'4" 145++. We are running offroad events and in our series he is stuck on small bikes until 16 . Anyway the bike buzzs along neck and neck with the FMF equipped bikes and 100lb riders.
You need to spend time with the dremel tool on the intake manifold. You have to cut it flush then match it to the gasket.
Boyseen Rad valve works well also. Some riders like them better. Atleast with Vforce you can set it to low setting to get more low end and midrange.