I've driven both. Now granted our C5 is a 2000 and I know there's been updates in the suspension as the years have past. That being said..
Our '06 C6, which by the way has the Z51 pkg. IMO handles more smoothly on the road than Our C5. I can honestly say (No Brainer) the C5 is a Stiffer ride, and doesn't have the same feel as my C6 when i'm cruising at 55 or a bit Higher.
Lets just say...I'd feel more comfortable taking a curve in a C6 at a higher rate of speed than in a C5.
Also, the cockpit is smaller on the drivers side (haven't sat on the passenger side yet)
, and has less leg room for someone who's 6'4". But the extra leg room in the C6, wouldn't matter to you
.
I do like the interior look of our C5 better than our C6 though. I like the seats better, I prefer the stereo knobs vs the push button, and it's just more appealing to me, Also the C5 Vert has more trunk space than the C6 Vert. (a little off topic, I know).
Haven't you driven a C6? If not, I wish i'd have known. I would have let'cha take mine for a spin!!!
IMO.... I love the C5 and the C6. I'd definately have bought a C5 if I hadn't bought the C6 first! If the suspension bothered me enough in the long run, i'd change it out.
~Ray