I put an OS 40 LA in my trainer when I was getting started a few years ago. The engine is very reliable and runs fine, but if I would have known better I would have bought something different. My problem is that now I'm stuck with an engine that is basically only good in a trainer. That's fine if you plan to keep your trainer forever. I'd like to junk my trainer and move the radio and engine to a new plane but I can't find a decent plane that is light enough for the engine.

If your a newbe who just wants a cheap/reliable engine for your trainer, the 40 LA is for you. In my opinion, the money you save will be offset by having to purchase a new, bigger engine when you start your next project.