I said it's "effectively" a one stroke as each piston has power on each stroke. Obviously there are two strokes per cycle but each piston is doing both strokes at the same time(compression on one side, power on the other). I'm not talking about opposing cylinders/pistons, I'm talking about two combustion chambers per cylinder for a total of 8 combustion chambers, just so we're clear.

Eventually I want to build a full size model and I don't know if I'll have the money again so I want to buy the best I can right away.