As somebody that's been driving a Tesla since 2013 (first the Roadster, now a 90D Model X), my experience is that the "best deal" is the one that involves a Tesla in your driveway that does what you need it to do. I have no doubt that today's Model X is a lot better than the one I got 2 years ago. But a lot better is something like the difference between a 9.5 or a 9.7 on a 10 point scale - you're awfully well off either way.
It's still the best car I've owned and driven on a regular basis by a long shot, and it's still a great car to drive.
And in 2 years, when whatever refresh comes to Model X after Raven comes along, it'll be even that much better than it is today, or it was 2 years ago, or the 2 years before that. No matter how it falls out, it's a great car at a falling price.
So you'll pretty much constantly have a reason to wait, sort of how cell phones were advancing so fast and furious early on, thereby providing a reason to not buy yet (because next year's phones will be so much better than this year's phones).
For myself - I think I've achieved peace by thinking about just how amazing the car is going to be when the loan is finally paid off in 4 or 5 years; that'll be when it's time to look at selling the current Model X, and getting all of the accumulated goodies in a new Model X at that time .
Completely agree! Well said.