Heck, I've seen new C5's around here for the high 30's. If $$ aren't a problem I'd spend the extra $10k for a C5. It will hold its value better too.
average mustang GT driver is in his late 40s... that said, average C5 driver is still probably 5-10years older.
The C5 is kick ass. Just make sure you buy one with the upgraded suspension. The FRC we have here at the house has the upgrade and it handles like a beast. The vettes that came with the regular suspension had a lot of body roll, so look out for that. As far as the car itself, it's fast, it's sexy, and it'll just put a smile on your face everytime you drive it.
Personally id Rather have the 05 Mustang but to each his own i like Musclecars Not Sportscars and thats what i classify a corvette as a Sports car (Skateboard with a Big motor) but thats just me i like a little bigger Car im 6'8 hard time for me to fit in the Vette plus i hate GM! to each his own Lead, follow, or get the hell outta the way!