SAE is good for classification but not for evaluating performance. By definition autosteer isn't "driving", but it does effectively drive for you at the level you'd expect, and it can take you 300 miles on a highway without disengagements and the $12k package can even overtake cars slower than you.
That's my point. Mercedes might be able to operate unsupervised on a some predefined map of highways while under a set of conditions and at a certain speed, but that doesn't mean it's a good product that solves real problems if it can't take over driving unsupervised on a regular road trip where you're driving 70+mph.
