Yes and I run 12 x 6s around 10k on a Saito .56 at close to the same weight as an O.S. BB .46 w/muffler. Still agree that the 2-strokers will turn higher RPMs and the 4s have the torque for larger (includes wider bladed) props at lower RPM. Slower, wider, fewer blades = better prop efficiency. Both types have a place for me and work quite well, if you overlook the differences in sound.

quint