I was running an APC 12 x 4 and recently switched to the APC 12.25 x 3.75. Hover is somewhat better with the new prop. The TT .46 Pro will hover the airplane but will not fly out vertical if the airplane gets way out of shape. Because the performance is so marginal, you can really tell the difference as the fuel load gets lighter! With a running start and quick application of power the airplane will pull vertical out of sight. Works fine for my use but I always stay a mistake high when hovering. For tail touching I use my Extra foamy with AXI 2212/34 - Yipeeee! I can not get the UCanDo to harrier like the other guys with the larger gas models. I don't know if the 2 stroke has something to do with it or if the airplane just does not do that beautiful of a harrier.