All of the initial reviews have been VERY good of the '10 GT500. Not only that, but it's been put on dynos and making over 500 hp at the wheels making it very much underrated (est. ~570 hp)
The interior is said to be vastly improved, and the drawbacks of a live axle doesn't seem to affect it as much as people thought it would. The steering and braking are faultless.
Keep in mind the car's value. For $45-50K you have a car that will embarass anything in its price range and then some. Because of the new CAFE standards, I'd say that there's more than a 50/50 chance this car might become a collectible.