My little quest for the last couple of years has been to see how fast I could get a .049-.061 powered plane to fly. Flat out speed. I tried various carbon props available from Mike Hazel and Steve Wilk, these guys have an infinite selection of 1/2A sizes. None of their props were noticeably faster for me than the $1.83 4.2x4 APC, so guess which prop I buy 24 of every year? I have tried the other APC props, but they aren't optimum for the tiny stuff I've been flying. My smallest racer has 105 sq inches and weighs about 10-11 ozs. Every racer and speed fanatic has a bunch of different sized props laying around, because only GOD knows which prop will be the best one for your particular engine / plane application. The 4.2s don't break THAT easy because there is only 3/4 inch of blade hanging out from the edge of the fuselage. I think APC offers a nice blend of affordability and performance.