Better all around. Nothing wrong with the 35S. It's just that the L.A.46 is user friendly, makes more power and mine is a one flip start. Last weeks contest I entered 2 classes and got 2 trophies. Can't ask for anything better than that. A lot of them are being used so there is a lot of good advice on these forums. They also can be run as a 2-4 break motor or run in a solid 2 or a solid 4 stroke just depends on what you like. The L.A.46 is a ABN motor and the 35S had a steel piston. Tower sells it for $79.99 you can't go wrong. Buy it, run a couple of tanks thru it, bolt it in and go fly. I have yet to hear a bad word on this motor.

An LA 46 is a great engine, very user friendly.  The OS 35S is also a nice engine, but the 46 just makes more power and is just a break it in, flip and fly kind of engine