A couple days ago I took a test drive in a Model S. I have a reservation for a Model 3 but not hopeful that it will arrive before 2018, given any number of reasons why it would delayed. If the Model S turns out to be everything I wanted I might consider cancelling the reservation on the M3. So the only option I can't make up my mind on is the Smart Air Suspension. My personal option is that SAS or just plain air suspension is problematic on most brands and is not worth the trouble. I detest service center visits to have something repaired, especially if I could have done without it. I have a steep drive entry and could probably use it but SAS is not a 'must have'. I can negotiate the incline by approaching at a slight angle. Is there really a noticeable increase in range efficiency? How say you about SAS? Has it been problem?