Let's just say that the S-Class tends to feel roughly as stable and settled (but still quieter) at 155mph when the limiter kicks in as the C-Class feels at 110mph.
Well, at least the models that were available back then when I was still living in Germany. It's been a while, I'm sure the "lower tier" Benz' have improved quite a bit since then. (Google "gentlemen's agreement" if you wonder why it's limited at all, and why to 155mph specifically.)
You basically just waft along as if the thing was sitting on rails.
But you obviously still need to understand the physics of what you're doing. I would absolutely not recommend taking ANY car up to that speed (even if it is specifically designed and built to handle it) if you don't already have experience with taking cars to (and beyond) their limit. Taking a car down the Autobahn at any speed above 100 or 120 miles an hour changes the physics you deal with drastically as compared to when you're chugging along at your usual 65 or even 80 miles an hour. When you are coming up to pass a car, you always have to keep in mind that they might not be fully aware of the speed difference, that there's always a good chance that they'll judge you to still be far enough away for them to pull out into your lane with not much of a warning. If you're going at 140mph while they're moving at 70, you will have caught up to them just as quickly as they'd speed past someone who was at a standstill. And given the fact that it'll take you about half a second just for the physical act to move your foot from the gas to the brake pedal — and actually likely considerably longer than that if you include the time it takes your brain to process all inputs until it fully realizes what's going on in front of you, especially if you weren't already operating at peak focus levels, which inexperienced drivers almost never are — you will have travelled enough of a distance in that relatively short time frame to leave you with very little remaining time and distance to burn off enough of your velocity to avoid rear-ending the mother and her three kids that just pulled out in front of you.
Even on an entirely empty road, you're still dealing with the physics of a 5,000 pound chunk of metal traveling at a velocity that most commercial jetliners take off at. That gentle, long curve ahead of you will quickly feel like a seriously tight, little hairpin when you plan on negotiating it at 150mph.
And even if that road you're on is brand-new, perfectly even, with no traffic in sight, and perfectly straight, you still can't be entirely sure that it'll be safe. My dad once hit a piece of 4x8 construction lumber that was lying across his lane on the Autobahn, and even at just about 85 mph it took his entire front axle assembly and oil pan pretty much clean off the car. It was late at night, and even with high beams and at "just" 85mph, you barely have any time to react to something like that. Do that at 150mph, and from the moment you hit that construction beam, you'll have travelled yet another 500 feet before the first parts of what's left of your car even just begin to touch the ground.
And the real "fun" part about it all is that you can have all the awareness and foresight in the world, you are still sharing the road with people who don't. Because even in Germany, with a few stretches of speed-limit-less Autobahn still remaining, and even with Germany's admittedly rather world-class (and world-class expensive) drivers' education, most drivers are entirely unaware of the physics they deal with in these kinds of situations.
Because I was a firefighter when I was younger, and because my town had a really well-equipped permanent drivers safety course where you could simulate all kinds of different situations, I was lucky enough to have had the ability to take cars past their limits and learn how to deal in certain situations if and when the schiit hits the fan. But because I was a firefighter, I also had plenty of opportunity to see the aftermath of what happens when you first run out of talent, and then out of road.
I wish that people would realize that even in modern cars with modern materials and safety equipment, hitting a solid, stationary object with as little as 20mph can in fact already be deadly.
Long story short: The mood that distant thunderstorm created, the music, the fact that I was driving to Berlin to see a crush, that's why I said that it was a rather special night. But also because I took that S-Class all the way up to the limiter, since that is something I almost never did even with my awareness of the physics that are involved, my advanced driver's education, and the relative safety of an almost brand-new, well-maintained car that's over-engineered to go that speed and still behave rather predictably and stable.
