I haven't been in your specific car, but I've been in and driven plenty of Model S's. Overall I find the latest Audi fully loaded system to blow away Model S with the Tech Package - and that's not counting the 2015 A3, which looks to be even better. Audi's Nav system in particular has the best integration of Google Maps, Google Earth, Google Street View and Google Voice Local Search of anyone. Just ask any Model S owner that got lost trying to get to TMC Connect a couple months ago...
Tesla has real estate on its side, but the system just isn't fully mature yet. What do you have on your 500GB hard drive? Is your Model S a wifi hotspot? Does it support 4G? How many cameras on your Model S? What about auto-parking, heads up display, lane departure warning, etc?
BTW, I don't own an Audi.
Tesla has the best passenger car drivetrain on the planet. It doesn't have the best infotainment system, just the biggest screen.