If this were a Ford or Vauxhall it would be acceptable. It goes well, is comfortable and quite well equipped. What it isn't is especially well built or particularly refined - the two key things which I would expect from a prestige brand like Mercedes.
The supercharged engine delivers the goods but is very rough and noisy when worked hard. It's not a pleasant noise either - just a coarse, featureless thrash, although to be fair the engine has been faultless. The auto box is the exact opposite - lovely to use but a bit temperamental, the ECU had to be replaced when it kept refusing to engage Drive.
The Sport suspension sharpens the C Class up nicely, and the car can be quite good fun to hustle along, although the traction control intrudes early on to slap you on the wrist if you're being naughty. The steering is very light, but has reasonable feel, and the brakes are strong.
The single real disappointment is the quality. You don't expect things like failed electric windows, dash creaks and broken glovebox catches on a main dealer serviced prestige car which has done only 47,000 miles.
This is a really good car which has a lot to like about it, but the bottom line is that it's not worthy of the image or the price that the Mercedes badge commands. My previous Rover 623 was just as well made, and had a more pleasant engine to boot.