I'd like the extra range simply because my family prefers to make fewer stops on road trips, and would like to make more road trips in the X instead of the Cayenne. I'm willing to pay for the upgrade price to the 100D, which I'd guess would be $10K if they offered it today. But a mid-four-second 0-60 time is fast enough for me, so the P100D is not that attractive. I jumped on the P85 option when I got my Model S in early 2013, but the regular non-P Tesla performance has improved so much that I no longer find the Performance option compelling. Hell of a compliment to Tesla's product line, IMHO.