Currently Model S lags waaaay far beyond pretty much everybody in satnav usability.
Sorry but I could not disagree with you any more.
I just went with my mother on Monday car shopping. She's coming from a 2014 Lexus RX350 (horrid nav and interface). The POI might be great, but having to scroll to each "C" and "X" is awful. We test drove a new 2016 Infiniti, and it was almost as bad. The only thing better was that the screen was touch-screen at least, so you can touch the letters instead of scrolling with a large button. I asked if it had voice capability, like "Navigate to 124 Main Street" etc...he said "yes", but you had to go through "prompts". So...no.
She wound up buying a new 2016 Porsche Macan, and the Navigation on it was just as useless. Same thing, "Type in Country, State, City, Street name, street number" individually. It was comical as the guy was trying to show us just how "intuitive" it is, while he pressed 8 different buttons to show us how to navigate somewhere.

Later he admitted that most of his clients just use their phone.
Yes the Tesla navigation isn't perfect. I usually cross check it with my Waze app (and usually follow the Waze guidance instead), but as far as using the Tesla for POI...it's VASTLY superior to practically anything else I've come across. In other words, I can say "Where is Home Depot" and it shows the closest 3 home depots so I can choose the one that is going to be closest to where I'm wanting to go. The Porsche (after manually typing in Home Depot) only gave me one option, and only in list format...not superimposed on a map.
Oh and the final kicker in Tesla's favor, they can make it better over time and send it OTA....Porsche/Lexus can't.