I've been a C4 fanatic since the car came out in 1983, and I'm still a C4 fanatic. I absolutely love the car. The styling is sleak and beautiful, the handling is out of this world, and it feels like a sports car should: a little noisy, a little rough, lots of power, excellent road feedback. This is a driver's car if there ever was one, and anyone who doubts me should drive a C4 on a twisting mountain road, maybe Highway 92 from San Mateo to Half Moon Bay. Being on that highway (barring heavy traffic of course) in a C4 and descending towards the Pacific ocean as you move around curve after curve, feeling the tires hug the road surface and hearing the hum of the engine, is a zen-like experience. IMHO, the c4 is the ideal corvette.
Now, I like all Corvettes, but my opinion of the C5 was fixed on the day I drove one. These are just my opinions, so you C5 people please don't send me angry emails. I love the power of the C5, but the car is too big. I also do not care for the style of the car, as many people have pointed out the rear is HUGE, I read somewhere that someone compared it to a giant shoe horn. I don't like the front end either, it looks like a Fiero or a Firebird. It is fun to drive the C5, there's lots of power and the handling is almost like a Cadillac, but road feedback is limited. Also, the cabin seems really pinched, the windshield is raked at such an angle that there is just a thin view out the front, the car feels really claustrophobic. The a pillars are huge, and the steering wheel should be light and elegant, not have four gigantic spokes. Overall, the interior seems so cheap, with rubbermaid window controls, and the little button pod to the right of the steering wheel moves up and down when you touch a button; the entire thing moves up and down, like it's going to fall off. The leather seat covers seem kind of cheap, like they made it too soft and flimsy, and I see many C5s where the seat covers are cracking already...very cheap. Also, the 90-96 corvette made use of expensive-looking LCD display panels for the dash, hvac, and radio, but the C5 uses cheap-looking LED displays that you can't read in direct sunlight. Who approved LED displays in the C5, it's like taking a step backward.
I'm not saying my 1989 is perfect, but overall it feels like a more solid sports car than the C5 I drove for a day. Sure my car is fifteen years old now, but every time I drive it people still point and stare. I love this car very much and will keep it forever. I'm very glad that the C6 appears to be a much better car than the C5: smaller, lighter, and leaner, with a much improved interior, so I'm saving my pennies to get one within the next year or two. But I'm going to keep my 89 coupe, it's a fantastic car.