My girlfriend has a 2009 Mini S with an automatic she got last fall. She loves it.
It's a great car to bomb around in and hers has been trouble free. However it only has 8000 miles on it, so who knows what the future holds for it.
Overall, I like the car too, the fit + finish is better than my new Impreza. Mechanically...not so sure. (just my opinion) These cars are kinda quirky and take some getting use to.
It's not the best for long boring drives, I found myself getting squirmy while on a turnpike drive at steady 70-75 mph for an hour, but if the road is tight + twisty, it's a blast.
Getting it repaired at a Mini dealer can get expensive. But there is a huge Mini following with many small shops that specialize in Minis along with a great selection of after market part suppliers to choose from.
I'd suggest heading over to the big north American mini forum, and see what is what with the minis. They have the good along with the bad and the various issues the minis are having.
Hope this helps.