We bought the first 5 that came in at our local hobby shop. We have one with a saito 72, power to burn. The rest have fx46's. With the stock mufler if barely pulls out of a hover. With an ultrathrust it is a rocket. Amazing how much difference a muffler makes. Just make sure you offset the engine, otherwise the muffler will not clear the wing. Mine was the first one together and guess what, the ultrathrust doesn't clear. I ordered a tower hobbies muffler which is almost the same gain in power. I need power.

The plane does fly great does everything you can ask it to do, and I think it is easier to hover than my 40%. Both thumbs up on this one!!!