Pro: Very stylish and elegant. I have the silver one with red interior. The SLK 350 feels very solid on the road. Mine has the 6M and it is fun and easy to drive. Cons: The navigation unit failed once, the dealer replaced it with a new one, it has been working fine since.
Love the retractable hard top with the real glass rear window. Also love the HID and Airscarf.
The interface of the navigation could be a little more user-friendly.