I have the OS46AX. It is my first experience with a glow powered engine. I was able to break in my engine in one tank of fuel, and had it in the air for the second tank. It had loads of power and operated without a hitch. Acceleration from idle to full throttle was really smooth, and it idled very smooth as well. It now starts with one simple spin from a chicken stick.

The ease, reliability, and dependability of this engine are remarkable. Guys at the field were having all sorts of engine problems, dead sticks, etc. And, the OS46AX has a newly designed muffler that makes it sound great!

While I have no experience with any other engines, I really don't even want to bother. OS (2 stroke) is the way to go, IMO.