All, I just wanted to add my comments to this post thread. I bought my 2008 ES350 in December 2007.
Regarding the transmission; at about 20 mph and during deceleration, it seems to "speed up" briefly before it slows down. It is slight but I feel it. It sometimes does is at 40 mph. Acceleration is no problem at all (in fact it is great).
Regarding the "creaking", I thought is was me but it has happened only 2 times in the 1300 miles I have driven the car. Each time, the weather outside was very cold. But it has only happened twice (and it has been cold more than twice). Thanks for the posts since I am due for my 1000 mile checkup and I am going to mention both items.
By the way, on the highway mileage, I could not be happier. My last trip this weekend was 200 miles (with about 20 miles in towns, the rest on highways/interstates) and I go 33 MPG!!!! Not bad for a 272hp V6 car like my Ultra Luxury ES350.
I hope the above minor issues get resolved (I could live with the slight transmission issues) but the creaking will have me extremely upset if it continues or gets more frequent.
Again, thanks for the posts!