I have had the upgrade performed and drivinf the vehicle about 4,000 miles, this is reaction:
Initial driving response much crisper shifts
I then started experiencing very hard shifts and brought it back the next day and was told that i would have to drive the vehicle at least 1000 miles before the new chip programing adjusted to my driving style.
After 2,000 miles the very hard *BLEEP*s between 1st and second and then to third have smoothed out .
overall shifts are much crisper ;) although the trany still has a massive hessitation when entering a highway with a 16 wheeler rapidily approaching I mash the gas peddle and it stays in either 1st or 2nd way way too long it appears that the revs are way up between 5-6 thousand rpm without the upshift to a higher gear.
I have gotten around this by releasing the gas pedel and stomping again but that takes precious seconds in a very un comfortable situation since that 16 wheeler is now on your bumper and is rightly ticked at me.
If I drive it like a manual, the response is better but that takes too long. So be careful; if you have the upgrade done expect masively sharper shifts in the lower gears. Unless you are a very experienced driver, I would not reccomend the upgrade.
I am glad I have had the upgrade done; my milage has gone up 2-3 miles per gallon and the shifts have been crisper with the exception of the very rapid acceleration from 0-60 mph.
Gene