You really are spot on with your description of the engine and the transmission. The delay in shifting is most bothersome. The delay is so prominent it's almost a saftey issue. This past week, I needed to change lanes quickly to avoid a car that was moving up fast in the left lane. I hit the gas hard and it took the transmission so long to downshift I barely made it past the car in the left lane. Kind of dangerous.
My first experience with a truly electronic transmission was the 4T80e transmission in the Northstar Engine. You want to talk about a world class transmission - this was it. The downshifts were faster than the blink of an eye. Any the overall quality of the shifts was amazing. The A6 in the Malibu is a highly sophisticated electronic transmission. There's no reason why it doesn't have the responsiveness that the 4T80e had.