A Model S owner should never "need" to charge at a L2 Public charging station unless he/she is on a road trip. I don't even bother with opportunity charging anymore. In my mind, the 30A public charging stations are for the Leafs and Volts, etc. At 18 miles of range per hour, it's hardly worth the effort to navigate to one, get the adapter out, swipe my membership card, and plug in. All of that bother, so I can pick up 69 cents of fuel per hour? No thanks.
On a road trip, my charging "order of preference" is:
- Tesla Supercharger, then Tesla HPWC (80A, then 40A), then a distant third would be 30A L2 Public charging stations, then RV parks for emergency only. I ignore the Chademo stations because I won't purchase an adapter. I read about lots of complaints with Chademo stations: ripoff prices, inoperative equipment, reduced current, time limitations, membership costs, etc.