I am more than pleased with my mileage so far.
GT/AWD on the east coast at low altitude. I live in DC and have been getting 27.5-29.5 mpg on my trip to work which is about 65% highway.
Recently I took at 330 mile round trip to a rural town in VA and back. On the way down, the computer read 32.6mpg (in the AWD too!). However, once I calculated it at fillup, I actually got 34.5mpg! I was very pleased. This trip was 95% highway and I kept it between 60-70. I'm pretty sure average speed read about 66 mph. On the return trip my girlfriend drove and she has a heavier foot than I. Needless to say, we got about 2 mpg less on our way home, still pretty good though.
I have hit advertised numbers and better. Will be taking a 1500 mile trip at the end of May and will post those results too. Shooting for 34 again!