Dave, saw your video, great clip! Went flying yesterday with the UCD yesterday and really tried to ring it out. Still have the stock muffler and enjoyed some short duration hovering (still learning)at 1/2 to 5/8 throttle, but it will not pull out with authority. I really appreciate your input as far as the engine performance issue is concerned, (I'm gathering materials for the MCP this week) However, I would like to ask you one more question. When in high alpha flight, such as harriers, elevators etc.. do you switch in to flaps, spoilerons ? And if so, how much? Again, Thank you in advance for any assistance as I really enjoy this plane. It is truly a blast to fly!!!