Tesla's solution offers a product that occasionally tries to kill you and people around you. The only reason it doesn't is because drivers are forced to pay attention and take over at a moment's notice at all times.

Mercedes' solution is a car company taking actual responsibility for their software. If they feel the lawsuits/insurance claims/legal snafus are worth the risk, that means their software is probably pretty damn good in that limited scope. Otherwise they could literally bankrupt the company with lawsuits! That's a lot more confidence inspiring to me than Elon's repeated pie-in-the-sky claims.