A couple of things for you to comtemplate. First, someone had suggested the linkage bowing.. which is a very good possibility, even though you have it flying to your satisfaction. The way to find out is to hold the servo with one hand and then try to flex the elevator with the other. If it moves, then it will move during flight, usually trying to center itself with the pressure against it in loops, for instance. The way to fix that is to use stronger linkage rods, or pass the linkage rods through tubes that have been secured to the fuselage formers. That's what I had to do with one of mine a while back that was behaving exactly as you described.

This is, of course, if you want to find the original problem. What you did was ok if you are satisfied with it's performance.

The other thing, well, a prop with a 6" pitch will do approximately 5000 feet per minute (theory based on prop size and 10,000 RPM) which is just under 1 mile per minute or just under 60 miles per hour. This is under perfect conditions, of course.

CGr.