Adding Boyesen reeds to a stock cage involves removing the stock reed stopper as well. On some motors this is very beneficial, some not so much. The stock reed stoppers can interfere with the intake boost port in some motors. I believe the standard reeds from Boyesen are a fiberglass direct replacement and will have little affect on increasing performance whereas the "Pro series" are a carbon fiber pedal that are much stiffer than a stock reed which will move the peak higher in the RPM range at a small cost to the bottom end. Gotta give to get, no free HP.
As for replacement cages, I prefer the Boyesen cages to V-force. No real science, just personal preferance.