I've just driven a couple of hundred miles in a CL500. It's a great car and a superb piece of engineering. In fact, with its lighter engine and better seven-speed gearbox, it gives the more expensive CL600 a run for its money.
It's got drag coefficient of 0.27 - so far ahead of the field that it's not funny - and is so well insulated that you have to have the windows open when you use the horn, just to reassure you that it works.
There's one small thing that bugged me, though. How do you turn off the sat-nav voice guidance? I browsed through what apperaed to be the entire car management system and I couldn't find it anywhere.