I know a guy that has a TT39 and he said it was a great motor, it has more power then the OS32. I have the OS32 and I can tell you one thing, it is a very reliable motor. I have never had a problem with mine. In my opinion it should have a little more power. If you are a beginner, the OS32 would be a good motor for you (very dependable). If I was going to buy a new motor for my 30, I would go with the TT39 (but that's just me). I have read some good things about it, plus I would like to have a little more power.