Maybe

I haven't driven this one, and I haven't driven the CSL. But according to stats (which may lie, as we all know

) the following would happen:
The CSL does 0-60 in 4.8 seconds. The SLK (standard 55) has been recorded at 4.2. Rumors say 3.9 for the 400hp version.
Top speed of the CSL is 250kph (limited), the same for the SLK. However, you can get the 030 performance package which removes the limiter on the SLK (top speed according to my dealer is 300kph as shown in their DB).
The CSL weight is just short of 1.4 tons. The currentl 55 weighs just over 1.5 tons. With the special version of the SLK, the weight should drop within reach of the CSL.
and finally...
The price of the CSL in Swiss francs, is just over 120k. The price of the SLK is 102k. Add the performance package and you get the same price.
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Anyway, numbers are just numbers. I believe in driving a car to find out for yourself if it's the right thing for you

Some people want power, others comfort, and so on... The SLK does it for me (for the moment). I'm still young and I want to believe that my future still holds automotive surprised (hopefully pleasant ones) in store