SF 25 or 28 motor gliders, choice of fine, coarse, or feather, and with a prop brake. Not a serious difference windmilling, mag off, in fine or coarse, but with the prop stopped the glide angle is much better. It is actually visible without needing to measure height loss against time. Feathered is obviously better again! We usually only leave it in flight idle long enough to cool the engine before shut down, and normal landings are as a glider, prop stopped, feathered and horizontal. I have to add that the coarse pitch setting is actually quite acceptable for a take-off on a reasonable runway, so not actually that coarse a pitch. One can stop the prop without using the prop brake, but it takes a while at just above the stall.