I don't use either one. I set up dual rates, but I never switch from high rates. Whenever I try to use expo I always crash (yes, I know its me). I don't like the feel of expo.
So now I set up all my planes for dual rates in case I ever need it. But I have yet to use low rates.
The guy who helped me get into jets always use full rates with a lot of expo (so do a lot of other people I know). That way you can have both without having to worry about remembering which switch you put it on.