OUTCAST,

It's not clear from your post what you compared to what. Did you have two planes which were identical except for the tail feathers and fly them back to back? If not, I don't know how much difference in performance you could expect to notice. Beyond that, you wouldn't really expect a night & day difference anyway, unless the flat surfaces were on the verge of stalling or something. Generally, that won't be the case. It's a pretty good bet that the tail surfaces with symmetric airfoil sections are more efficient at generating the lift they are expected to generate, and it is almost certain that they are lower in drag. Whether you notice it, or whether the benefit is worth the extra building time, is a different story.

banktoturn