I agree, it is best to just try a Vess. I have been running the 26A prototype on a 3W 80 and ZDZ super 80 for sometime now. It just outpulls the others I tried hands down (mejzlik 26x10, PT 26x10, NX 26x10). The 26A loaded down the motors about 200-300 rpms compared to the PT and Mejzlik, but was night and day better. The best example is my friends AW 75cc yak with the super 80 (stock muffler). The airplane is a tank at 25.5lbs, and the 80 pulled it around with decent authority with the PT 26x10. Not ballistic by any means, but pretty darn good. We put the Vess 26A on it and the airplane came alive, it is now ballistic, just can't put into words how much harder it pulls. I don't have any affilliation with Vess, except he sent me some prototypes to try, so not trying to sell you anything but give honest feedback. The 26A for 75-85cc engines is THE PROP in my opinion.