This is one great all around car. You can easily obtain 27 mpg on a highway trip, but combined your looking at 20- 21 mpg(still not bad for a v8). When I was purchasing this Impala I was also looking at the 08 Honda Accord 4 cyl. They were almost the same in price, but a huge decrease in Insurance on the Impala SS. I couldn't believe it. I have had no problems with this car. Chevy's are great quality cars.
The 5.3 v8 (of course). 4 cyl deactivation is great for the increase in mpg.
The seats need to suck you into the car more. They need more lateral support. Front wheel drive is nice when you are in the snow, but i miss the thrills of a good burnout. (how I miss the rear wheel drive)