From what I've heard, and read on RCU over and over again, is that the TT engines are really hit and miss. I'm getting the impression that about 80 percent of the TT engines arn't built properly. However, some people get a TT engine, and it works great for them. Its hit and miss.

If it were me, I would, without a doubt, get a OS engine. I'm going to be building a 50 right shortly, and I will be getting a OS 50 Hyper engine.

If you like the deals you get when you buy a raptor with a TT engine, you might want to consider getting a helicopter combo from HeliProz. They seem to have great deals with OS engines, not TT engines. Check them out, www.heliproz.com

I hope this helped,
Best of luck,
Carlyle