No experience with the T-Clip, but have been flying a Revolver for 3 seasons. Actually, assembling #2 plane now. Finally managed to destroy #1 to the point of no repair. What I wanted to add is that the Revolver is built like a lightweight brick. It uses foam core wings and stabilizer, so it's REALLY sturdy, allowing it to handle 20cc very nicely. I wouldn't call the resulting power outrageous like you might find in an all out 3D plane, but I would suggest it's for seasoned fliers. Somebody mentioned prop size, which is a good point to consider because of ground clearance. Normal 20cc will be looking for 16 or 17" props.

If the T-Clip is of conventional construction, a 15cc gasser, or even the 10cc Evo might be good options?