I totally agree. I was surprised at the acceleration the engine delivers ('99 XJ8). It's even better now that I have cleaned my throttle plate and cured the slow-speed stalling problem I had.

 

Don't get a flush...just drop the pan, swap out the filter and fill back up with the appropriate fluid. I used Pentosin and have no problems for the past 500 miles. I only had 50K miles on the OD, but there was a significant amount of gunk on the bottom of the pan and around the magnets. I plan on swapping out a couple of littres per oil change until all of the fluid has been exchanged (that which was left in the torque converter). I have been told by a tranny specialist that this was the safest way to change the fluids on an otherwise 'sealed for life' unit. Flushing a tranny that has done more than 50K miles could equate to trouble, if not immediately, soon after. If you would like to do a 'safe' flush then you could try this proceedure:

Disconnect BOTH ATF cooler lines at radiator and place a container or pan under each line end (helps to have an assistant). Start engine, shut down after 1 or 2 quarts have come out one of the lines. Refill exact amount of fresh fluid in transmission (this keeps air out of the system).

Start engine again and repeat until clean fluid is coming out of cooler line. This is messy and time consuming but will purge all old ATF from transmission and torque converter. Then, reinstall the cooler lines and start the car; cycle through the gears, place in park and check the level per owners manual. Check for leaks. Top up as necessary after driving and heated up. Don't overfill.

This way youhave safely flushed the whole system...