I think Elon Musk is right that 200 miles of range is a magic number. Without that, range anxiety can kick in for a variety of simple day-trips that you might want to make. For example, it's a 57 mile drive from my house to the beach. With only 100 miles of range, you'd have to worry about charging somewhere near the beach. With 200+ miles of range, you don't even think about it.
We own an 2008 A3 (petrol) and a 2013 Tesla Model S. In terms of "interior quality" (seats, trim, etc.), I'd say they're roughly on par with each other. In terms of frequency of visits to the shop, squeaks and rattles, and other such things, the Audi has a slight edge on the Tesla, but both have been much much better than, for contrast, my 2000 BMW Z3, which was a never-ending series of problems.
Today, there's exactly one serious competitor to Tesla in the U.S. market: the GM Bolt, which is going after the same segment as Tesla's Model 3, except you can actually go buy a Bolt today. Not so much (yet) for the Model 3. On paper, the Model 3 is a much nicer car, with the fancy AutoPilot and a beautiful interior, but none of that matters if you can't actually get one.
To my mind, Tesla's greatest contribution to the world was serving as an existence proof for a kick-ass purely electric car. Once other car manufacturers start selling serious competition, we can have a fun discussion about which cars are better or worse. It seems that the first serious German competition to Tesla will be the Porsche Mission E, which has already been seen doing the Nurburgring.
Fun hypothetical: let's say my Tesla is totalled through no fault of my own or of its own (e.g., a valet driver crashes it into a wall) and I could get a Porsche Mission E or a Tesla Model S for around the same price with roughly the same specs. Which would I buy? I'm not sure, but I'd welcome the chance to try both. I'd probably end up making a decision on all sorts of secondary things, like whether I can fit my bike in the back without removing the front wheel. (Plenty of room in the Tesla for this.)