As first time Model S owner, I wanted to mention a couple of reasons (/rationale ;-)) why I went for the p85d.
Handling. It's wet a bunch in PacNW. I've always owned AWD/4wd cars here. I like to slide cars occasionally for fun, though sliding a rwd car unintentionally is never fun with family in the car. I also drive over the mountains here pretty regularly. I've both test driven and "played" in s85, p85, and found them to have a loser back end than I liked. We have a model x on reserve (though unfortunately missed the sig opportunity), and kept getting emails and calls to (presumably) convert us to the Model S. They failed as we still have the X on pre-order... Oh, hang on...
I like quick cars. I was seriously considering the GTR and the release of the 2015 with 2.7 0-60, seemed ideal. It was vetoed by my better half reminding me our children have legs and, even if I squished myself into the steering wheel enough to accommodate their unwarranted request, she would prefer it if the children didn't have to invariably climb over the front seats to get in (ie 4 doors please)
I LOVE the torque and performance characteristics of an electric vehicle. Ever since first driving an old RAV4 EV, I knew there had to be a way to get myself driving one.
I try to think of how to do my part to reduce non-replenishable energy use
I respect the way Tesla has built up over time. They are not perfect, though strive to learn from missteps, not repeat them, and do better with a "one team" mentality. Their communication is perceived as poor, though I trust they'll find a better balance over time.
Netnet: I could have gone for s85d, and indeed the reason I wasn't signing up on day 1 was that I had a hard time justifying the ~20k (a nice car in its own right) of additional cost. I didn't as a) I'd already waited ~5 years for this type of car and b) my better half took pity on my continued slobbering over p85d, and said "life is short, you deserve it". I ordered that same day, and haven't regretted a moment since. I respect it as a great feat of engineering and the fun if is
Anywho, opinion is just an opinion. I think all Teslas are great and one day I hope to pick up a roadster too. Once the children have gone to college... Right? ;-)