If you've been waiting to buy one of these, do it now. The new C7 version will probably be smaller (maybe even a V6?), probably have less HP and will be a completely different vehicle. This car is a screamer. It will literally "snap" your head back with its' acceleration. Roadabilitly is sharp, handling is precise and once you get on the fwy. mileage is more than acceptable (22mpg). The runflat GY tires make the ride a little stiff but you can replace those. All the other option packages are nice. Maintenance is a bit more cumbersome and expensive (needs synthetic oil and a special filter) but manageable. This car can be used as an every-day driver.
Bose stereo (upgrade) is awesome. Z51 suspension is nice. 2-top option isn't necessary (if you can just use the see- through fiberglass top). And last but not least, 400HP is truly breathtaking.
Needs better tires (there are much better runflats than GY). The present Firestone and Michelin offerings are much better choices. Repairs can be expensive (with all the on-board computer hardware - so you might invest in a GMPP = ext. wty?).