Since no one mentioned the GMS , I`ll give it a shot. I have a GMS .47 with the large expansion muffler. It was hard to tune the first few tanks, once tuned in , the power and rpms it puts out is unbelievable . I dont have a lot of run time on it , so I can`t comment on durability .

The OS .46 AX is a great engine for some one who does`nt have much experience with glow engines . Very easy to break in and tune.

Evolution engines are great if you get a good one.

SuperTigres are my favorite for any size 2 stroke. lol