Lots of typical non-owner-of-W220 comments here. My folks have one, among half a dozen other Benz models, and it so far has given 77000 miles almost trouble-free. Did blow a catalytic converter a month or two ago, and both cats were replaced free by the dealership even out of the car's warranty -- Benz even picked up a $600 towing tab on that. It has been a fine, comfortable, safe car for highway use, and it's sure a lot better looking than the shoebox W140.
(What would you get if Scion made their cars large? W140s, but probably without the AC problems that cost as much as a Scion does in the first place!)
Cheers, John