Originally Posted by Charlie P.

IMHO it's more a matter of personal preference than anything a model requires. I have none at all on some of mine.

You won't know how much you need until you fly the model. And you may even change your mind several times as you get used to that particular model and how it is balanced and the throws are set. Guys flew VERY well for many years before it was even an adjustable feature.

What I found was that anything over 40% - even on hot 3D models - just makes it a jerky on-off-on sensation to the stick and becomes counterproductive. Instead of finesse you have to bang the sticks around. I don't believe now I have anything over 35% (that is on my little 15" EDF Sabre that is tres squirrely to elevator) and normally I use 25% to 15%. Just enough to lessen the center for landing or smooth, straight flight. I normally fly high rates throughout the flight.

Had a bad one when switching between transmitters and thought I was switching to low rates for a fast pass and instead hit CROW at speed with my Hot Stik. Did an instant 90° down and I pulled out just in time to shear off the landing gear (which tore off the horizontal stab) and rip up the teeth of all four aileron servos. Thought I had saved it until I walked over and saw it was a fatal pancake. Learned a lesson on being consistent with how I assign switches on my various transmitters.