I think the MAS props are far better for mixing paint, but the APC are better for flying. I knew Fred Burgdorf quite well when he was getting Landing Products off the ground, and incidentally worked for Chris Machin of Rev-Up back in the 70's while in college. Both were making the best product in their respective era, and sadly both have passed on. Machin made his first prop in 1949, and last one in 90's after he lost his wife. Burgdorf started in the 80's with a lot of help from his brother Otto. Something like 30,000 lines of code to mill the molds. The difficult part was the transition between the blades and the hubs.