Very excited to have taken delivery of our P90D Production Model X! I've added the info to Model X Tracker.
So far there are no major problems at all. I'm sure we'll find a few middling issues to report to the service center (such as some rattling coming from the passenger side at higher speeds, and squealing physical brakes at very low speeds. Doors work great, sound system is great, car drives great, car charges great, and the seats are very comfortable.
My biggest complaint so far is that the second row seats seem to have a mind of their own, seemingly trying to contradict my wishes at any given moment. Middle seat especially doesn't follow any logic that I can determine. I'm hoping Tesla will eventually release an update that reprograms the functionality of the second row so that it's easier to put the seats where you want them, when you want them. And where the heck is "Cargo Mode"? How difficult is it for Tesla to add a command to move all three second row seats all the way forward? I guess it's difficult enough for Tesla to allow manual control of the headrests, so maybe moving an entire seat is too much to ask?
Still, small complains aside, the car is fantastic and my wife is loving it. Maybe she'll let me drive it one of these days...!