My brief impressions:
Drove a grey performance with pano and (allegedly) upgraded stereo. Driving experience was fantastic. Handling superb - far superior to my current BMW 750ix, my previous BMW 540 and my Audi S8. It wasn't a 911 but incredible for a big sedan. Carved through the turns with virtually no body roll - you can really feel the battery weight and that is a good thing. Comfort level of ride superior to the BMWs, not as good as the Audi. Accelaration spectacular. 0-60 was a blast and 50-80 also fun - speed limited to 80 on test drive. Note that I understand that guys who say it doesnt feel as crazy as 4.4 0-60 should -- without the violence and noise of sawing through the gears it is just a different experience - but it was a blast. Also was able to chirp the rear wheels off the line with ease.
Interior - while not as bad as some have said, it is kind of lacking. Plastics, particularly around doors, are hard and cheap-looking. Seats have no lateral support - which is a huge problem given the performance capabilities -- I was constantly sliding out of the seat. Not a showstopper for me but I can understand those who won't pony up 100K for a 50K interior.
Stereo - this is a big deal to me, second only to performance. Unfortunately, there wasn't time to really explore it. Also - and I suspect this is just a beta problem - my usb stick with lossless AAC would not play despite best efforts of two Tesla reps. But radio sounded as good as radio can sound. Not a big bass system but clean. My standard is the B&O in my old S8 - best car stereo I have heard (crushes Lexus/Levinson, BMW, Acura etc). Model S wasnt nearly as good (based on limited test) but likely not a showstopper.
Any questions - fire away.