I have a AMT 450(45lbs thrust) in mine. Lots of extra power. I did replace the stock tail pipe with a larger one. I had a Ram 1000 in it at first and I can't tell that it flies all that much different other than the extra power
I am getting a 10 min flight on 1 gal of fuel. I am only full power going straight up. Have landed dead stick once and it floated OK. Mine is the old version so it is heaver(30lbs dry) than the new one. Hope this helps.