CatWoman,
Wouter speaks a lot of sense. But as the above-mentioned Spitfire sailor in his reply, I must add that I love my Spitfire too!

I was comparing its one class design nature to the F18s, which have evolved. If you buy any current cat, whether it has the latest sail shape or not, you can bet that when it comes to re-selling in a few years time, your sailplan will be out of date. It is arguable that it will be less out of date in a one class design such as a Spitfire... And if you are not planning to re-sell and to sail recreationally, are you bothered about a few percent in speed? I thought not!

As a Spitfire sailor, I would think you need to pay most attention to any desire to sail solo - the Spitfire is a two-up design that I would sail solo in light-moderate winds but not race it solo in strong winds.

Have fun
Simon