I drove it to work this morning, that's all I've driven it thus far.
It's fast.
It has great torque. The supercharger engagement (it has a clutch) isn't perfectly smooth in my opinion, but that may have to do with how I was modulating the throttle, and could have to do with the mileage. More research is required, it could also be that the clutch is going bad and in need of replacement. I love the low-end torque, and the engine has a great sound to it. Basically the same engine as your CLK430, just bigger and with a blower. Because the blower is clutched, it really has two power modes - with and without the blower. Without it still is very torquey and responsive. With, it's just fast. I got on it and highway acceleration is great. It almost never goes about 3,500 RPM thus far, and has no need to. I did floor it and let it get up in horsepower. It's much nicer than my VR4 was, even though it makes about the same horsepower. The VR4 was reasonably torquey, but very laggy. This has no lag, and way more torque. It has something around 520 ft-lbs of torque I think, and 469 HP.
The cruise control will maintain a set distance from the car ahead of you (which is adjustable). This is actually a pretty nice feature and one that I enjoyed using. I guess I tailgate people, though, as I set the distance at the shortest allowable.
The tires are pretty close to bald (I expected that) and it needs an alignment, so I need to get that done.
It has a brake fault, not sure why, and the brakes feel pretty numb. This is a complaint on these cars because of the fully electronic braking system that has no physical connection between the brake pedal and the hydraulics. I need to investigate further and figure out first off what's wrong, and if the brakes are doing what they should. They don't feel like they work great, I need to do a hard stop still.
It's quiet. Not entirely whisper quiet, but it's also 13 years old with 190k on the clock. I haven't pushed the suspension much, but it has an air suspension. I do like the fact that I can adjust it for "comfort" or one of two sport settings. My back roads going to my house are a bit rough, so the "comfort" setting is nice for those. Sport for the highway is nice, although comfort does just fine. The engine makes a very nice rumble, AMG got the exhaust tuned about perfectly. Supposedly the SL55 has a slightly different exhaust which creates an additional 15 HP.
The interior and exterior wear like iron. They're immaculate. This is one of M-B's hallmark traits, in my opinion, and part of what drew me to the car. If you didn't check the odometer, you'd think it had 1/3 the miles it does. The seats also have a bunch of adjustments, which I like. I need to play with them some more.
For the high miles, I still feel like I got a good car (at least today) given that I don't expect to drive it for more than a couple of years. We'll see how I feel about it after I drive it more.
One of my friends is trying to get me to get a custom plate for it. I've never had one and they're cheap enough here, so I'm considering it. The following options have come up (all of which are available in Kansas):
TRACTOR
ATOBAHN
CLOWD9
310FLYR
IFLY310
BYBYCOP (that might not be a good idea)
FLYTWIN
MOREPWR
Feel free to come up with more options or give your opinions on the options above.