Good old blood red Amsoil ATF all the way in the transmission for me.
Kerma line pressure mod at 32 "clicks".
Car is bone stock (for now) but will spin 1st gear if you floor it from a stop on anything less than perfect traction pavement. The shifts are firmer but I have not heard it bark second or anything neck snapping like that.
I drive at WOT (wide open throttle) allot... on a WOT acceleration, if you lift suddenly the car noses over hard like it is downshifting and hunting for gears much lower than your speed would otherwise call for. These shifts on decell feel really harmful so I am avoiding this condition in all but emergency situations by lifting slowly from WOT if I am below 80 mph or so.
In other words don't floor it at 10 mph and spool up the turbo to say 50 mph and then lift your foot off of the throttle suddenly. These particular parameters are not accounted for very well IMHO so I avoid them.
I only got just less than 2 quarts to drain from my trans pan when I did the filter and Kerma mod. After the first refill, I cycled the trans through the gears with the engine running several minutes and drained and filled a second time to get more old VW ATF out and more new Amsoil ATF in. Another drain and fill was repeated a couple of days later as well. I plan to drain and refill every 10k oil change and do a drain, filter and refill every 20k miles.
I always cut trans filters open and look for paper and metal bits... that will tell you much about the condition that your transmission is in!
My 2000 automatic may fail short of my 250k mile goal, but it will go down shifting firmly and will be nice and clean inside when it does give up...