I own a Mk1 and I've driven a Mk2 a couple of times. In the end, I decided that for the money you're looking at for a really mint Mk2 (£16k+) you can have a truely mint Mk1 with the same miles, cambelt done, and £5k in your pocket - which helps with the crippling fuel consumption.
The Mk2 interior is miles better, with more toys, no way round it. Personally, I think the Mk1 front end looks better, more aggressive. They're identical from the back. As a sweeping statement also, from been on V6Clio.net for 6 months, Mk1s seem to be as reliable if not more so - maybe because they weren't actually built by the french heh
But they are all better built than the run of the mill Clios in my experience.
As for the performance - we had a little play in a little convoy to the FCS - only up to the legal limit of course
- and in a straight line up to reasonable speeds there was nothing in it between the Mk1 and Mk2 - at all. I expect at really big speed the Mk2 would maybe stretch it's legs a bit more.
Handling, well, the Mk2 is safer, understeers more, the Mk1 is immense fun but if you take the piss WILL kill you - the Mk2 is the same if *really* pushed. In the wet they're both best left to pros to be driven hard. I tend to just pootle in the wet - because I'm so NOT a pro heh. There is easy 2nd gear tail out action to be had in the wet though - although personally I really don't want to practice this on the roads heh, there is too much to hit.
That's my thoughts. The Mk1 still draws a crowd and always has people stopping to look, take camera phones out etc heh. Great way for talking to birds
Dan