I've been enjoying my P90D for just over two weeks now and aside from a few minor cosmetic issues that have been well covered in other posts, I am pretty thrilled with the whole experience. My expectations for the X were pretty high given I've been driving a Porsche Cayenne S for a few years, and I was a little worried that the X was not going to measure up in terms of comfort, style, and overall driving experience. Today, after not driving the Cayenne for over a week, I took it out on an errand and wow was I surprised at how much I missed the X even for such a short drive.... as great as the Cayenne is, the X is just far above and on another level.
I can only speak from my experience, but to those who have had build problems with their already delivered X's, my recommendation is to document and give Tesla time to correct them. It is clear that the design of the X is solid and that the majority of the vehicles are not having substantial issues -- which is pretty amazing given how many revolutionary features have been included in this vehicle.