Seen a couple that run as good as any OS. Seen no make that runs better. Seen some special purpose engines that run better than general purpose and that is apples and oranges.

But EVO's don't all suck. Some do. Most don't.

Their idea of an already broken in, factory adjusted engine with limiting devices has some merit. The idea is wasted for flyers who are smart enough to seek out experienced teachers, but it works for those who don't.

I've never seen any make of engine that was a guaranteed loser, and that includes the blister packed McCoys from the 60s. But the only guarantee of getting a cheap engine to work and work for awhile is to put it into the hands of a smart, experienced modeler. Or maybe just blind luck will do it too.

There are good engines and there are cheap engines. And the ones that are predictably good are usually not cheap. And often are marked OS.