I have my Saito 91 on an AeroWorks Extra 260 weighing 6.5 lbs. The APC 15X4W pulls good but the spool-up is so slooooow that it is hard to get a stable hover. The woods, 14X6 MA Scimitar is pretty good but the XOAR is better, give a much much much faster spool-up and make for a much easier hover. Go to Paul Swanny's website (google it) and he highly recommends the XOAR props. He also makes one of the best 3D profiles on the planet (Mojo). I have yet to find anything that works better on my 50cc Extra than XOAR.