So, update after 2000 miles, and 22 days.
Still loving it. Electricity aside, it truly is a great car.
It turns more heads than my RS6 ever did, and from a far broader range of folks admiring the electric motor silently moving along.
I will, in the interest of balance document any downsides I have found to date:
1) The ordering process. Its nothing like as slick as you might want. You go online, pop it in your basket, and commit to buy it with a deposit. Then, you sit patiently hearing nothing. It was a very frustrating experience, and logistically a nightmare for me (having no car) and other folks who had leases coming to an end etc. They have a lot to learn about the motor industry, but I think they are listening.
Agreed: they're constantly playing catch up with their growth and trying to balance demand with their resources supporting this. But that frustration soon evaporates (is forgotten?) once you get your hands on the product 
2) Service centres. They are still few and far between, and they do seem quite overwhelmed still with the surge of Model 3 demand. I am a little nervous that if this piece of tech wonder breaks, only they can fix it, and they are pretty busy. Its a small concern, but a concern nonetheless
You (probably) don't need to be nervous: there is so much less to go wrong than in an ICE car, and if it's major, they're pretty good at fixing it quickly, without the usual rigmarole of the "traditional" dealerships.
3) Spotify. Its great, but keeps crashing. Its a real shame, its the only thing that does seem buggy, and when your tunez crap out, the journey is rubbish. Various workarounds now exist, involving switching to other inputs for a bit etc, but its a distraction for sure.
Weird. Never had that, worth checking.
4) I have a minor rattle at high volume from the passenger side dash area. Its actually a compliment to the (a) quality of the audio kit and (b) the standard of fitment of the rest of the cabin that one single rattle is annoying. I will do some DIY diag on it at some point and try and work out exactly where it is - if a simple push the trim back properly doesn't work, I'm sure Tesla would sort it for free, subject to service centre availability
One for a ranger (mobile service technician) to look at - the sort of thing you could trying booking under the service option your phone app.
5) There are no grab handles. Its an odd omission. There are coat hooks in the rear - But sometimes, especially as a passenger, I like to hang on, and can't in this car....
Lucky you - at least you have coat hooks 
That's pretty much it on the downsides.
The upsides, I don't have time to write about right now. There are loads. I find it hard to believe I'd want to ever go back to the hassle and cost of having an ICE car. It really does feel a completely last century device. I've refused point blank to drive the Q7 since the Tesla came along. The turbo lag is verging on dangerous, and it has an annoying rattling noise at the front.......
