I've had my 2008 C6 for a few months now, and I've been driving C5's for about 5 years. I'm quite blessed to say I presently own both C5 and C6 Corvettes, so here are my thoughts comparing the two. I'm going to start with the body and then move to the internals, and finally end with my personal thoughts.
Both cars are quite beautiful, but I find that the C5 has my eye more than the C6. From the curves on the front fenders and hood, to the doors and quarter panels, I prefer the looks of the C5. However the C6 is about 6 inches shorter and when trying to squeeze things in the garage, it does come in handy. One point in the C6's favor are the taillights, more of a traditional circle instead of the C5's oval. One real issue with the C5 is the possibility of leaks around the windows. My two previous C5's (RIP) never had any issues, but my present 2004 does have seal woes. I've adjusted the window among other things and have only managed to make it better rather than completely solving the problem. The C6 like many modern cars has windows that drop down slightly when the door is opened and then raise back up when the door is closed. Though this can be an issue when temps drop below freezing, and especially when snow and ice get on the car (yes I drive in all sorts of conditions), aside from that, they don't suffer from the leaks the C5 does. The last major body difference I've found is the hood. The C6 hood is much smaller, lighter, and easier to close than the C5. Frankly, it's better.
As far as interiors go, my C5 has the electronic package and the magnetic ride suspension. My C6 has the electronic package and the nav system (base suspension). The C5 HUD is more analog than the C6, by that I mean the characters look less digital, they are also larger. The C6 HUD does have three modes however, track 1 & 2, + street. I like both so I'm really torn to say which one I prefer. For gauges, overall the C6 wins, though I do like the blue dot line display of the C5 as compared to the green readout of the C6, but I'm nitpicking at this point. Other than that, the C6 wins no contest with the gauges and frankly, the entire rest of the interior. The only thing of note is the lack of the storage compartment where you would think to find a spare tire that the C5 has, though neither has a spare (runflats for both). however, this is partly where the C6 saves those 6 inches of length. Overall the C6 wins for interior.
For driveline, the C5 has the LS1 and the C6, the LS3. Both are great powerful engines, and I don't push either hard, but for those interested, the C5 2001-2004 has 350HP and the LS3 C6's have 430HP. They are plenty quick for me... Gearboxes (6 speed manual on both) have the same ratios but the C6 has a shorter throw. I Like both, I'm no racer so having a longer throw and a different feel doesn't bother me. I like both in different ways so I can't really chose a favorite. Both cars are very similar and can share parts. I like working on both, oil changes are easy, my tools work on both, pucks are the same for lifting, and my boards for raising it just enough so I can get a floor jack under it work fine on both. Both cars use essentially the same frame and overall setup, so not much is different from a maintenance perspective. Both cars are amazing!
Finally the driving experience. I thoroughly enjoy driving both cars (I'm not planning on selling either for quite some time) but I have to say the C6 does beat the C5 in this slightly (surprised? You probably shouldn't be). The C5 has more of an analog feel and is more old school, the C6 is more digitized, and has a newer feel to it. The overall feel of the steering, suspension, steering wheel, and interior is better in the C6. However, I intend to keep the C5 because it is beautiful to look at and I do like the analog feel of it. The C6 also has a much better sound system for those long road trips.
In conclusion, both the C5 and C6 are amazing cars. I highly recommend either, but if you are torn between the two, go for the C6, it is an improved C5 for everything except the looks in my opinion. You can't go wrong with either though. Happy driving, stay safe, and God bless!
