Well, Fredette only does KDX's, and Eric only does porting and motors... the RB mod includes a divider plate on the carb, as frp is just a bore out, and re-jetting.
I have heard great things about eric's work, but on this one, I might have to swing over to frp on the port work, especially on the 220's as I have heard that eric still can't cure the lack of topend on the 220. If it were any other bike besides the kdx, I'd go eric all the way... but Jeff Fredette only does KDX's and that counts for quite a bit.