I keep seeing the adds for these things and I am curious about them... Are they as poweful as a regular .60 2 stroke? Reliable? Prone to overheating? Are they really the size of a .46?

(P.S. I think two of these in a .40 size twin would be BA)

Yes they are the size of a .46, and yes they are as powerfull as a full size .60, but only with the smaller props. They are awesome in small fast planes, and really come to life with aJett muffler (Evolution performance muffler) or pipe. They will turn a 10-8 well over 15,000 rpm. The stock muffler supplied with engine is useless in my opinion since it is to small, and runs horibly with it. That said, they are screamers, and will really impress you with it performance.

About the only other sport engine in a small case that can out perform the 60NT is a Jett 56. Some(me too) have have found the Evo carb and tuned muffler combo can be cantankerous in mid range, but an "in flight mixture control can make it absolutely tame from idle to WOT.