My $.02 is that stuffers work well on smaller displacement motors like a 250 two stroke MX motor, thats why they use them. If they are so all around great, why didnt Yamaha put them in their watercraft engines? Also, you would think PWC engine builders of our time would recommend them for their engines if they were so great??
OK, so now with reed stuffers you are running a much smaller opening for the intake charge to go through. Sure, it speeds up the charge, can give a better carb signal, and can give a bit better low RPM throttle response, but hit mid and top RPM's and its a choke on PWC engines...
IMO, spend your money on good set of Vforce reeds and a A/M manifold and your set!