[cobrashoch]

Dave - The auto drivability for your C6 is EXACTLY the same as a C4 and the AOD's from their derivatives. Ford made AOD based C4 and C6 locking converter trannys and hot rod tranny builders generally switch the converters over to nonlockers and manual shift bodies. Generally the locking converter trannys are avoided due to the limited converter choices you have.(i.e. the costs) As stated above the electronic shift stuff requires a external brain box.(more costs)
The C6 you have now is the heavy weight of the bunch in both weight and componentry. For that reason it takes more power to drive it (lost power to the rear wheels) than it's smaller brothers. Excepted power loss is around 85 horsepower on stock C6's and as you tranny gets older and wears, that number will go up. You can have lightweight components that help both power and it's strength but the overall picture was cast at the factory.
That brings us to where we are now on tranny thinking. The original thinking on ALL of the big three's heavy boxes was that the heavier componentes would take the higher power numbers better. We now know that the heavier componentry is the CAUSE of breakage and failures. Todays trannys are designed with lighter stronger componentry that belay that old thinking. This current thinking will also transfers more power to the rear wheels. So generally thinking smaller is better, overall.
At the top of current thinking is the G.M. powerglide. The tranny I bought from Coan requires only three or four horspower to drive it and can withstand over 1500 horspower. And it was built with the street in mind. So as you can see the megga shifter is the least you can do!
Cobrashock