I fell in love with this car, the handling, and the wonderfully powerful and smooth engine. I continue to enjoy the well-crafted and reliable engine (each engine is hand crafted by one person, and signed by him/her) and the excellent ride. And the car looks sharp, inside and out. But I will bot purchase another Mercedes. The "cons" are just far too many for a car that is $140K+. I average 13mpg (city driving), premium gas only. I have had to buy new tires on three occasions now (with less than 15,000 miles) They are fat tires and pick up all nails and cannot be patched. And tires are $500+ each. And reliability of non-engine components (electrical system especially) is awful.
Engine -- the sound (purrrrr) and performance. Speed. Design and handling of the vehicle.
Mileage is horrible (10 - 13mpg city, at best). Poor tires. They have to be replaced often (more so than any other sports car I have ever owned). Very poor reliability for electrical system and other componets.