I owned an Original JCW 210 (supercharged version).
For sure there were good points and bad. Let's start with good:
The steering was quick, even faster than the Clio 200, yet not frisky or twitchy like the Clio can be at high speeds. The front end had a beautiful pointiness about it on turn-in.
The throttle response on the supercharged version was immense; instant torque as soon as you even think about touching the throttle pedal.
The Mini had lovely mid-corner adjustability as well; trully felt as though the car was rotating around the gearstick.
However, there were some misses too.
First of all, the obvious - there's absolutely no room in the back for actual human beings, and the boot is less than half the size of the 200's.
People bang on about the build quality of the minis, but actually I'd say the rest of the small car segment has caught up now and I wouldn't put it any higher than the Clio.
Drivingwise it was great at 80% - plenty of low and midrange grunt, pointy front end, snatchy gearchange and enough adjustability mid-corner for a bit of lift-off oversteer.
However, under real pressure - either on track or when really going for it on a deserted, well sighted road, it all got a bit messy. The front end tended to get a bit scrabbly, inside wheel lighting up, stability aids flashing up on the dash and the car inevitably slipping into understeer. The lack of top-end fizz robbed you of the satifsfaction of holding onto each gear like you do in the Clio. Althought there was more torque in the Mini and a greater powerband, it wasn't a patch on the rev-hungry nature of the Clio engines.00
Basically, up to 80% the Mini is great, but above that it all goes a bit pear shaped, while the Clio just gets better and better the harder you push.