I had an evolution 46 that came in a trainer. good motor had gobs of power. it had alot of unessaceary stuff on it but a solid motor.I think the regular 46 does not have all the extra stuff on it.like fly wheel and limiting collars and stuff. If i where loking for a 60-75 motor look at the Gms / Tower motors they are nice motors. but for overall no hassel fuss long life and less frustrations get any size of OS in any type of stroke. saito makes a good moter as well .same quality as OS but a bit lighter. I woild not hesitate to get a evolution again. but i am going to move most of my stuff to 4 strokes. I am going to try Magnums next time maybe in a H9 pulse or a high wing plane with flaps. Heck, most of these motors are good everyone is going to have a bad egg every once in awhile. evo's have a good warrenty so does Os as well as Saito and magnums. take your pick don't let every onehere try to scare you into buying the most expensive motor. the best thing is to see what most folks in your area is running that way if you have trouble they can more easily help you. I really like the 75 GMS or Tower motor and if I ever get a plane that size and want a two stroke that is what I will get. Great bang for the buck and runs good too.