I have a 04 LS430 and as far as the transmission "lag", I have ABSOLUTELY NONE. If I push on the accelerator too quick it literally jumps. I've learned to accelerate slowly to keep it from "jumping ahead too fast" In fact after the new transmission was installed I saw no change in this.
As to the new transmission...I've driven about 300 miles and so far it has worked just fine. My service advisor said they had installed several and none so far had been returned. As to the time to replace the transmission, my work order allowed 4.5 hours and for the fuel pump, .9 hours.
My service advisor knew nothing of a $200. gas card. He said all cars would be filled with gasoline when deliverd to the customer. Unfortunately, I had just filled up a few miles before I took it in for the work....
I guess the only way to lay this $200 gas card to rest is to call Lexus....