CLS looks nice but thats based on e class chassis
True, that older E-class chassis wasn't very stiff, and the electronics had a lot of issues. It was the worst Mercedes for Quality Control when it first came out.
I imagine the new CLS (soon) will be a lot better.
The most fun car I've driven was a V8 Audi S4, the all-wheel drive contributes much to it's driveability.