well if you got the S2000 i think you'd probably be annoyed at it for having about as much torque as a fisher price "my first hand drill" until you get the vtec system kicking in.
in the z06 you can go from 0 to like 175 or something in one gear. you could easily pootle round in 6th in smooth quietness when you dont wanna drive like a loon. can do that in the honda, tho the honda might be a nicer place to sit interior design and quality wise. but at the end of the day the Z06 is just so good you dont care than they spent about 49p on the dash board.
both cars are going to have horrendous ride quality on normal roads though, the honda might be a bit more supple, but its still going to be a bit jarring. normal C6 hasnt got the fabulous engine, but the suspension might be a bit more forgiving as well.
i think by getting the Z06 your getting a great car, by going the other route.....your getting two good cars, id rather have one great one...plus 7 litre 500Bhp = mucho respect