I traded my E350 4MATIC for a Certifyed 2012 C63 AMG and I am very satisfied. I was offered the extended warranty, however I declined. Instead I invested the money in a separate portfolio just in case the funds are needed.
I don't believe in extended warranties, besides being a car nut I never know how long I keep the car. I missed my ///M3 (my wife found the car too noisy ~grin~). So when the right car with the right interior and wheels came along I made the switch.
Both the C63 AMG and my 280SL get along very well as garage mates. Mind you there still is a new 500 or 550SL in the cards, perhaps as a Euro delivery. Maybe next summer, time will tell.
Dieter