That is exactly what I was going to say, word for word, I had an ex demo 2018 Cross Country Estate and I used it for a long journey this year (July 2018), around 2000 miles racked up in a few days of all different roads and traffic scenarios.
Apart from the Maps Update and Vibration at 80 mph it was exactly like that, the guy who programmed them was probably the same wanker that programmed the Grand Picasso, that's another pile of shit to drive in the real world
As for that braking actually working, it depends, big vehicles and certain colours, like Red Sprinters f.e. it simply does not see them, I am absolutely convinced it would have hit them, when coming up behind them at around 50 - 60 mph, it did not brake full stop, I had to absolutely smash the brake pedal when down to the last 6ft or so, conversely, at slower speeds it will be well back from a small light coloured car at 30 mph rolling traffic and then smash it's own brakes on when there is no need, full on application of pre safe belts, whiplash the works
The twat who programmed it is a fucking moron who should have been sacked when Electronic Ignitions first came out !!
The Mercedes system actually work flawlessly, it is almost like you are driving it yourself