I am a newer to the hobby, i have yet to use expo's, but I do use dual rates. I feel expo "reduces" your feel for the plane and control, i like to think of it this way, when you drive a new car the steering wheel is very tight, but if you drive a car that has a lot of miles on it, you can just about turn the wheel all the way around before it turns, both will get you to turn but one will be a bit more jerky, especialy to a new driver.

hope that helps

Jon