Calling 911 from a mobile does not always get you to the correct 911 service center for the area you are in, and the 911 people don't have access to the GPS information. I believe that all the cars that have teleaid have the GPS receiver. When the SOS is called, whether you are pressing the button or automatically due to airbag deployment. The operator knows immediately where you are. If the SOS is automatically called by airbag deployment, teleaid people will call you immediately. If you do not answer, they assume that you are unconscious and dispatch an ambulance immediately.
If you could change to 911, you would be picking up less service in the case of an emergency, not more.
Heaven forbid that you will ever need the use of your tele-aid. But I would highly recommend for your own well being and that of your family, that you read the information in your manual so that you know what to expect and how to have the best possible life saving service in the event that an emergency ever arises. Nothing will prepare you better than a little reading and understanding of what this valuable system will do for you if the time ever comes.
I understand that there is a lot of information about the new electronic MB to learn, if you ignore the rest of the information, you owe it to yourself and your family to know about the tele aid.
Good luck and I hope you never need this information,