I just flew my new 4.75 LB PIZZAZ, all I can say is wow. This model with the Magnum 46 xls and tower muffler is hovering at a little under half throttle. I am now getting 12,900 with a APC 12.25 X 3.75 with WC 10% 80-20. The biggest problem with this combo is that the power needed to hover is low in the the power band so transition is tricky to maintain a hover. I am glad I made a framed up stick tail and pull-pull on the rudder, and tossed the axles and tires. Has any one compared the APC 12.25 x 3.75 to the APC 12 x 4.?