I started out with an Avistar with an OS46FX. The engine was a little difficult for a newbe to tune and I did have a couple of dead sticks because of it. Once you get over the tuning of 46FX it has TONS of power and I flew the Avistar around at no more than 3/4 throttle (with the last 1/4 in case I got into really big trouble).

I wanted to upgrade from trainer so I picked up an ultra stick 40 I moved the 46FX to the stick and stuck a 40LA in my Avistar. The Avistar with 40LA is fun to tool around with but has little "safty power" and you have to worry more about power/speed management.

The best part about the 40LA is the reliablitiy. It always starts and doesn't quit unless the tank is empty! Yeah the engine is cheaply made and isn't a power house, but it should be just fine for a trainer. Just keep it 2 or 3 mistakes high!