As a recent buyer in 2010 I feel somewhat late to the game, nevertheless I also feel compelled to state an opinion on my recent purchase (within the last two weeks) of a certified pre-owned 2005 S2000. My gawd, what a vehicle and I feel that I got a great deal being pre-owned, according to CarFax there was only a single previous owner, no accidents, and only about 11k miles per year. The closest vehicle I've ever owned before was a 2000 Mustang convertible (purchased new) and while I liked that car, frankly it couldn't hold a candle to my new (used) S2000. The handling, acceleration, overall performance, just wow, fantastic! I've owned about 10 cars in my lifetime and this one beats them all.
A true sports car, with an appropriate engine and transmission, as well as the matching look and feel (e.g. form-fitting driver compartment, highly-responsive steering, six-speed transmission, etc.) The convertible top works great, it's fast (i.e. about 5-6 seconds up or down.)
The radio, it's a pretty poor quality sound. I also had a really annoying rattle from the passenger side until I moved the seat up an inch or so for a further separation from the roll cage, that solved the problem entirely.