We had ours set on 20'C, driving over to the Lakes yesterday, and it was decently chilly - a little too chilly at times! Didn't seem anything wrong with the cooling capacity at all. I have heard a few comments, though, about the cooling power of current VAG cars.
Have to say that no car I've had since has matched the ability of my Golf GTTDi Mk4 to maintain 22'C all the time, whatever the weather.