The great majority of the Tesla Destination Chargers that I have visited (all in California or Nevada) were limited to 40 Amps, so a second charger in a Model S would not have increased the charging speed. With Tesla de-emphasizing dual chargers by no longer making them a factory option, I suspect we won't see many new Tesla Destination Chargers be 80 Amp powered. Depending on the electricity situation at the host location, it can be much more expensive to install a 100 Amp circuit than a 50 Amp circuit.