Only drove the National circuit, not the GP so couldn't comment on it, but worth a shot for a day, if only to say you've driven it! It is a track so it'll be fun either way

 

Its the most boring circuit i have driven/raced at. unless you have a car that is very powerful then its not much fun.

Mallory/Lydden/Knockhill would be more suited to the power of the S2000.

The complex before the start straight is fun in the wet though.

 

Drove Silverstone a few years ago in my 1st S2k.

I quite liked it but there is a sense of "waiting" for the corners to arrive, although you're flying, the width of the circuit diminishes the feeling of speed.

Secondly, to "enjoy" it you need to be driving fast round the twisties, really pushing the car. This what makes it fun, however it's also what makes it dangerous (or scary) if you're inexperienced (I'd done some track days by then but not that many but could see how much fun taking more speed through certain corners would be). Basically not one for those wanting a feel of track days and having a lot of fun to boot.

There are a few corners to get the back out in which I rather enjoyed Club corner and Bridge through to Woodcote. Basically the 2nd half of the lap of the full circuit. Many layouts used skip the bits I liked best (Stowe through to Club corners).

Bedford is better for fun at all levels, I did my first 2 days there and loved it. You can also enjoy it without having to be right at the limit all the time like Silverstone.

Brands Hatch (I've done more here than any other track, full GP circuit too) is great, however it's quite daunting at times as it's easy to hit things off the track if you get things very wrong. Possibly another one that's more enjoyable if you've done a few trackdays previously.