On my GW Yak my buddy had a OS 120AX on it swinging a 16/8 prop. When I bought it from him I put my DLE 20 on it. With the DLE 20 swinging an APC 17/6 prop she out performed the OS in all aspects. There was no way the OS could pull this plane out of a hover like the DLE 20.
The OS will not swing an 18/6. My DLE 20 will though it seems to be the happiest with a 17 inch prop.