So, just to throw in an experience which is different from the crowd: I reserved a Model S the day that Superchargers were announced (24 Sep 2012). I was not willing to buy the car sight unseen, however, as I am 1.95m (6'5") tall and have experienced cars which I do not fit in. So, I made a trip to Seattle (Bellevue) to test drive the car.
I was happy to learn that I fit in the front seat, but I was not too happy about the ingress/egress (I'm used to it now). While the car was great to drive, it didn't strike me as $100,000 great to drive. But that was really me just rationalizing not wanting to spend that much. I kept waffling... at the time I had a Nissan Leaf, and I was ecstatic just to be able to drive electric. I didn't need more range, though there were times it would have come in really handy.
I was still going to get the S, but with delays in delivery to Canada pushing it out likely past the change in taxation and incentive in B.C. (the difference being about $8000), I decided to cancel and reserved a Model X instead.
That lasted six months. The $5000 B.C. EV incentive was restored, which helped psychologically. I just managed to gain the courage to throw $100,000 at a depreciating asset (and take a hit on selling the Leaf) because, what the hell, it was worth it. Plus, I didn't have to wait - I bought the Vancouver service centre's demo car. I don't regret it for a moment.
So, the question I would ask is: do you have any reservations about the car that would be addressed by a test drive? If so, arrange for a test drive. If not, then don't sweat it, because all that you read about the Model S from the enthusiast owners out there is true. I think that once you've driven the Model S you really won't want to drive anything else.
I do miss the heated steering wheel from the Leaf. That's about it.