To understand why I think the Model X is such an amazing vehicle, first you have to understand what does not exist in the North American car market.
1) There is no vehicle that is AWD and fuel efficient. I wish we had an AWD diesel Subaru in this country. The best in this country might be the Ford Escape Hybrid which gets 30mpg at the best (not good enough).
2) There is no vehicle which is fuel efficient and can easily seat more than 5 with the exception of the upcoming model S (: Why hasn't Toyota made their AWD or even their non AWD Sienna a hybrid yet?
3) Now for the most difficult: there is no vehicle any where in the world that I know of that has good clearance and does not suffer from poor handling due to its high center of gravity, at least not one that also easily loads and unloads more than 5 passengers. Some of the Subaru come close minus fuel efficiency and people and gear hauling. The Model S comes close with the air suspension but can't be considered to have truly good clearance.
The genius of the model x is the batteries lining the underside in a high clearance vehicle and the front and back engines. With this you get power and AWD, without sacrificing fuel/energy efficiency. You get clearance without sacrificing handling. You get tons of human and cargo space with this because the batteries and all the trappings of an internal combustion not taking up space. Add to that the extra length you can get and still decent handling because of the extra rigidity that the full length batteries give you. It is classic case of genius where you take a problem (heavy space consuming batteries) and make it an asset: low center of gravity, space savings, and increased handling due to the increased frame rigidity. Tesla really has a winner in engineering here and the model x is the pinnacle of what can be achieved by this genius approach to electric vehicles.
The biggest challenges that remain, is cost in a difficult economy, dealing with subjectiveness of what people think is a good style, and learning to mass produce and service unique cars on that scale. If you have not guessed by now, I am obsessed with finding the best possible vehicle ever and this is the first one that comes close. I personally do not like showy vehicles and would easily trade "style" for a cheaper car with the same functions. In the case of the model x, give me the mini van doors at a lower price. Still I am as happy as a clam with the model x. It solves so many problems so elegantly.