I ordered the premium interior- I agree that it's worth the money. The base headliner is identical to the one in my base Mini Cooper. It looks and feels like mouse fur- the color doesn't match anything else in the interior- actually, color isn't really the right word since it lacks anything resembling color. Imagine the absence of all color, and that's the color. We got the black alcantara (pronounced suh-wade), and I think it makes a huge difference.
The power lift gate is nice, and saves me from having to listen to my wife and kids slam it shut. I haven't seen the lights in action (interior or exterior), but I'm hoping the cornering lights will sort of function like the active headlights I've had in other cars (and which Tesla really should include).
The base Tesla is a relative bargain IMO, but the interior looks cheaper than a $20K VW Golf. (If you don't believe me, go look at one). The premium interior with Nex Gen seats and the Pano roof looks more like the interior of an $80K car should.