Quote:
"Actualy this is not correct. A four stroke has nowhere near the torque or horsepower of an equivalent displacement two stroke. "

Well actually that is not absolutely correct.
While the fourstroke does only develope power on every other stroke ,the four stroke fills the cylinder better and compresses the charge more effectively and burns the charge more completely.
This allows for higher cylinder pressure which in turn produces more torque for a given displacement. They are able to swing larger props at lower more efficient speeds. Horsepower is a function of Torque AND RPM . Propeller efficiency falls off at higher rpm and four strokes are able to make power at lower RPM taking advantage of the increased efficiency.
The more efficient burning allows for a huge savings in fuel and a lighter take off weight from the lower fuel load.
The two strokes also need to run huge mufflers to bring the noise level down . The size and weight often overcomes the weight advantage of the bare 2 stroke engine. And the mufflers themselves usually do very little for the asthetics of the model.
4 strokes are less prone to loading up and accellerate more cleanly after extended periods at low throttle.
I know among flyers there are a few who like the sound of a two stroke better than the 4 stroke. Among the NON flyers who put forth the effort to shut down fields the two strokes are the noise that makes for most of the complaints. We have been involved many times with neighbors and almost without exception the four strokes were far more acceptable from the sound standpoint. If all we had to fly were two strokes our flying field would be a Soccer field by now.

The YS 91 rivals most 91 size 2 strokes power wize.
And the planes perform very well.

For WOT from take off to landing where noise and fuel consumption are of little concern the two stroke may have a slight edge

Another quote :
"And now for the other side of the coin....."

Thanks for the offer but I know 2 strokes, I hve been around them most of my life. Will I go back to them ?