c) The system needs to detect worsening conditions early either prompt you to take over with enough time to spare (or fail gracefully).
That's the big thing that Mercedes guarantees here: You'll have enough time to take over even if you're doing something else; if the system does fails to give you a warning in time and you crash, Mercedes takes the responsibility. In all other systems, once the autopilot prompts you to take over, you are responsible. With this system, once the autopilot prompts you to take over, Mercedes is still responsible for the next ten seconds, which should be more than enough time to take over in an emergency.
Oh well, we seem to have different opinions about whether a 10s-to-react-window in quickly moving car qualifies as having to be alert all the time. Fair enough.
c) The system needs to detect worsening conditions early either prompt you to take over with enough time to spare (or fail gracefully).
That's the big thing that Mercedes guarantees here: You'll have enough time to take over even if you're doing something else; if the system does fails to give you a warning in time and you crash, Mercedes takes the responsibility. In all other systems, once the autopilot prompts you to take over, you are responsible. With this system, once the autopilot prompts you to take over, Mercedes is still responsible for the next ten seconds, which should be more than enough time to take over in an emergency.