Despite the fact that this is the shortest luxury car available, it is extremely luxurious and refined, with very good handling (excepting steering), ride, and impeccable fit and finish. It is very refined, the most refined car I have owned (and I also own a BMW and a Porsche). The configuration of the car: length; visibility; practical trunk, folding back seats and 4 doors; coupled with perfect proportions and 4 wheel drive make it a car for all seasons, both figurative and literally.
The build quality and comfort; quiet, which makes the superb sound system a truly pleasing addition; visibility; ease of parking because of its small footprint, tilting mirror and a rear view camera; reliability thus far (5,000 miles); lever type cruise control; exterior lighting makes the car visible and easy to see from; extremely handsome looks; purchase price relative to all other luxury brands.
Fuel economy is very poor (the car's lifetime mileage is 15.3 mpg) and requires premium; the navigation, iPhone, and voice recognition system is poor, counter-intuitive, even opaque and requires use of an awkward cursor rather than a simple touch screen, and expensive; the rear seat knee room is very tight (would prefer several inches more wheelbase and length all in the rear seating area); steering and turn-in is numb not precise and overly assisted at highway speed; the rear view camera could be informative, provide guide lines; steering wheel controls distracting and unintuitive; blind spot and radar cruise not standard.
Gave up my Infiniti G37 for the C300. Narrowed down my choices to four vehicles. MB was the last dealer I went to. Turned out to be the best deal. Love this car!!! I have about 1000 miles on it and it has been an absolute pleasure to drive. The transmission is smooth as silk, and it is quiet. I now understand why people buy one Mercedes then end up owning them again and again.
Solid but comfortable ride.
Incredible sound system (upgraded to 7.1 Surround).
Roomy comfortable seats.
Intuitive command center.
Very good mpg - avg 24.7 city and hwy combined.
More cup holders in in the front (perhaps on the door pockets?).
Ability to keep the front led lights on without having the headlights on at dusk.
Cruise control on the steering wheel.
It's in an awkward position behind the wheel.
Warning system on the backup camera.