My Mum had one for 6 months and got rid of it. In that time, I had it for about a week for various reasons.
My view....
The supercharger whined far too much for so little progress. In fact, it got on my wick and ended up short shifting so it didn't kick in. Just as you got going, you had to change gear. A 5 speed box would almost be better IMO.
The ride was OK, but I must have different views to all these journalists, and found it very unforgiving over rough surfaces.
Finally, the paint took ages to get anything out of it. It was a black 06 Cooper S with Chilli pack.
On the plus side, there's not a lot to polish as so much of it is glass! She got rid of it as the driving position and seats were giving her a bad back.
Loads of people love 'em. I'm just an old school Mini person.