I had a n/a one. Great fun on the road, as others have said nothing touches them for handling. But as Nick said they are a pain to get in and out of, they do steam up badly in the cold, you may as well not have a stereo because you can't hear it at speed due to the noise behind your head (although the engines are brilliant) and the view round the car isn't good either, the mirrors are too small, I put blindspot mirrors on both of mine to make it a bit better but it's still not the easiest, especially in the dark. I used it to go down to Peterborough to work and come back in the dark and it's quite scary trying to overtake because you can't see properly.

But on a nice sunny day with the roof off blasting down some twisty country lanes there's nothing that'll give you more of a laugh. It's like driving a high powered go-kart. I let my mate have a go and he said it felt like being on a Play Station, that's what the steering wheel's like.
I must admit I didn't have mine a very long time because the cons ended up outweighing the pros because they're just impractical on a day to day basis. But I bet they're fab on the track.