Getting one is like kicking old Granny out of the 5-speed mustang's driver seat on her grocery run and letting John Force row through the gears. Who do you think would get to Walmart first?
Seriously tho, by changing the way your aod shifts, and by altering WOT shiftpoints your car will be a different beast. It will also prolong the life of your tranny. When it eventually dies tho, I would suggest a t5 transplant.