You either want the trailing edges sharp, or blunt. The pitching moments get unstable with round TE's and flutter is more possible as well as poor trimming and tracking qualities. Sharp is great, it reduces drag. Blunt is second best - small drag penalty but much easier to make consistent and hangar rash much improved. In the air I'll take sharp, and on the ground I'll take blunt. I need a shape shifting TE.

All my nicely molded pylon racer planes for electric have nearly razor sharp TE's. Those things are glass slippers - the meaning of efficient and fast.

I like the diagram Bob included! It's an easy way to show what people have "observed" over time but in an objective, measured way. I can use this for scratch builds, THANKS Bob!