I went out with my GP Extra 300s Power OS BGX-1 the first prop I used is the one I hover it with APC 18x6W not much for torq roll the next prop I used was the APC 18x8W makes it easier to torque roll (torque speed faster) Than I used a Zinger wood (lighter) 18X10 almost the same as the APC 18X6W then I used a Zinger 18X6 wouldn't torque at all but rpm real high then I used a Zinger 20X8 torque roll very slow fell right in between the APC 18X6W and the 18X8W (for what its worth) this is what I came up with and had an enjoyable day in S.D. for a Dec. afternoon wind 5 to 10 42 degrees a little chilly standing still though. Carhart Coveralls is the key word for today. and those funny gloves with no finger tips. Happy Flying!!!