I traded in my 2005 C6 with z51 for a 2008 base model 6m with just the Z51 option. I purchased the new 2008 for just under 42k(thats around $800 under invoice. The new car is almost like a night and day difference. The new c6 has a much nicer interior, much tighter and quiter ride, much better shifting and steering and last, but not least, the power of the new engine. I can defenitely tell the difference in acceleration. I think Chevy under estimated the 430 horses to make a larger gap in horse power for the Z06. This new car is just simply amazing.
New engine, nicer interior, much improved transmission and sterring feel. Standard OnStar, XM radio, auto dimming rear view mirror with compass.