I got the 2006 SL500 in Feb 2006. I am really a Jaguar person, having owned three so far, but at the time Jaguar would not even quote a price for the new XK, and I was able to get a good deal on the Mercedes. Well, the car is nice, but certainly not thrilling. Perhaps the SL55 would have been better for me. I consider the wonderful 7 speed automatic transmission to be the car's forte. It seems to be just in the right gear at all times. I keep the transmission setting in "sport" mode. The AMG package with the steering wheel paddles is a nice touch and I like the optional panorama roof. I must say, no car I have ever owned has attracted so much interest. My clients always ask how I enjoy it.
Strangers talk to me at the gas pump and strike up conversations. I suppose that is a charm of the car that cannot be ignored.
The buttons on the steering wheel that change the radio station should advance to the next preset, not the next "searched" station. That is the worse thing I can say about it. ;-)