i got the 450 in her and wow much better but ther is one small thing i forgot to mention i am in utah at 4500 feet and i guess that makes a difrence in the flight performanse also but it is great now with the 450 in it oh and BTW they only gave me 1/2 my money for the 400 because i used it even though the owner told me thats what i need i guess its time to find a new LHS