. I use dual rates a lot, but have been advised by many veteran pilots to not use the expo or any form of mixing etc. until I have mastered conventional. Their thinking is that although it will make things easier when flying close to center position, it will also be a crutch to a learner, and make him dependent on it. I am heeding their advise.

The above from "secondchildhood" post is one way to look at this situation. I frankly don't agree with not using expo and will have a student use it from the beginning. The reasoning is that radios don't give linear response (particularly around center) and make controlling the plane more difficult and much more likely to be to over controlled when landing. I don't see this as a "crutch" but as a tool to make the plane fly better (and as it should) from the beginning since it is used as part of setting up a new plane.

EXCAP232