I've just reached the 10,000 mile milestone under my ownership in the Countryman Cooper S All4. I've had it 10 months and it now has 25k on the clock.
It's a cracking little car. Well made, comfortable, practical, handles well, performs well. Acceleration is pretty brisk (0-100 is about 20s) but a Manic Motorsports remap may be on the agenda, which will increase power to Cooper S Works levels (circa 225hp). The only thing it's needed so far is new front and rear brake pads. It's not due for a service until the Autumn but it has TLC for the next 3 years anyway. MPG isn't wonderful - I'm averaging 32, but to be honest I don't really care that much which is why I bought a Cooper S one in the first place.
It's been just what I needed, a real jack-of-all-trades type of car.