The unique UX of the site, driving around in a 3D car, is what makes this site go viral on occasion. If it were "good" UX, e.g. a standard portfolio site, no one would care and this guy wouldn't be as well known as he is. Therefore the UX is good.
I think it's not a website you make to get hired to make business websites like this to display information (unless maybe it's a gaming company), but if you want someone to make a game on the web then this is a perfect portfolio site.
I agree, I was comparing it to the title of the hacker news post which initially said "Most impressive 3D website ever" or something like that. That enticed me to believe someone had figured out a really innovative way to make a website work in 3D.
As a portfolio to demonstrate your three.js skills for web game making it's really good.
