Ive never tried an Ostler air stripper but when I had my Daystate Mk3 FTR I tried a UK Neil, a home made one with adjustable cone and a unknown make along with the standard Daystate stripper. I set two chronos up, one at the muzzle and one at 55yds and I got the same results (in FPS) with or without either stripper and even with no stripper fitted! the only difference to downrange velocity was different pellets / batches. I also never noticed any difference in the amount of wind I give either. Not tried the test with my Steyr but removing the double cone stripper makes the gun very "flippy" for the want of a better word.