For the money, I would add my name to the 'O.S. .46 AX' list.

This engine will take you through your second plane. I began to learn hovers with this engine on an ultra-stick .40. I did not, however, finish learning hovers on that plane. I think I still have most of the engine.

If you find it a bit heavy for a trainer, just move the battery back an inch or two further till it balances. Trainers can take PLENTY of extra weight, but adding lead to a plane is like...giving-up.