Have has this car for 8mo/8K mi and overall I'm pleased, but there are a few things holding it back from being truly exceptional. The car is stunning. It looks like a much higher end model than the rest of the C-class. I get people stopping me all the time. It is also the most comfortable highway car I have ever been in. The ride is dialed in perfectly for highway commuting, it gobbles up miles by the hundreds in quiet, ease, and refinement. It is not without it's problems however. I have had many interior quality problems, a persistently squealing brake problem, and frankly, it's not all that sporty to drive. If you can tune out creaks and rattles, this will still be a great car for you.
Styling is fantastic. I'm slightly embarrassed to admit that I have stood in my garage and stared at it. Extremely comfortable. Great grand tourer. Engine is VERY smooth and refined, all the way to redline. Good tech features, bluetooth, ipod connectivity, sat radio, sat nav all work great. Blindspot monitoring system works so well, I may never buy another car without it (this car does have some rear-quarter visibility issues). 4matic is brilliant, car feels extremely well planted.
Have had A LOT of problems with rattles. To date have had to fix rattles from: nav screen, instrument cluster, glove box, rear deck, driver door speaker, passenger door, center console, front dash speaker, and a new one from the pano roof which has yet to be addressed. I also have a loud creak from the center console when I corner with any speed. It's like driving a styrofoam cooler. This sort of quality problems
are unacceptable from a $51k car (or a $25k for that matter). Transmission very slow to downshift, better in sport mode but defaults back to economy every time you start it. Beautiful car, great ride quality, great tech, but would not buy again because of the interior quality.