If you are talking about switching tunes on the fly?
IMHO the ability to swap tunes on the fly is WAY overrated.... IMHO
What I have found is I rarely have a need to change tunes..
I leave the HIGHEST HONKING hp tune I got in the truck and ration out the power with my right foot
but I do leave my tuner in the glove box all the time just in case...
believe it or not it will get the best mpg outta all I have tried and drives just as normal if I let it..
if you are talking about swapping tunes in the tuner - piece o' cake too - downoad some software from sctfash, plug the tuner in and load it up with files sent from your dealer...