Excellent point!
Again, response curves are sooo varied between controllers. My CH stuff needs a bunch. The 'S' curve is generally a good choice for the Rudder but not much else. Notice how I also have a 'flat spot' around center to help remove the twitchyness when firing the guns!
A big thing pilots is to insure that when you input 100% with your controller that the plane receives 100% response. Example...even though my Throttle is totally calibrated it's input to the game is only 82%...go figure. I use the response curve to adjust so that when my throttle goes to 100% the plane receives 100% input.....not 82%
As you can see above, an S-curve would be no good for the throttle. Here's how I adjusted the input vs. output to insure that 100% input = 100% output. If you have this wrong your plane will always fly....slower!
Best luck to all here. I will help when I can but if you don't have CH Pro stuff then there's little I can do for you!