Since this transmission thing has been talked about for a long while, there seems to be no solution to this idiosyncrasy by Lexus or anybody else. This topic(thread) has been pinned, and not too many people are looking at it anymore.......that's the reason you didn't get a response more quickly.
Yes, the ES330 continues to have this transmission quirk! Lexus states that it's caused by the "Drive by Wire" electronic throttle rather then the transmission itself. In reality, it's more annoying then a danger, in most instances, by modifying your driving you can control this hesitation to some degree.
"All-Wheel Drive" refers to vehicles that have permanently engaged or automatically engaging four-wheel-drive capability. The ES330, or any of the ES models never had this feature....they are front wheel drive only.
Transmission modification updates were automatically installed at the factory after certain VIN numbers. Previously, these updates were done by individual Lexus dealers at the owners discretion. This software update just changed the shifting pattern and did NOTHING to help the hesitation.
The Moderators & Administrators are just guys like me who like to help out members who have questions or problems related to Lexus automobiles. They are in no way affiliated with the Lexus(Toyota) Corporation.
Finally, I think the best thing for you and your wifey to do would be to test drive a new ES and draw your own conclusions. There is the strong possibility that you wouldn't even notice this slight hesitation.
I've been a Lexus owner since 1991 and I feel that the build quality, smoothness and quietness can't be beat.