It was indeed pretty awful. The area was tiny, no natural substrate, all inside, hundreds of screaming tourists, a really shallow pool with fountains and yes this is a critically endangered species. The MGM Grand lion habitat is so much better and the lions are only there a small percentage of the time.
Redpanda summarized my feelings towards the big cats in Las Vegas, and I personally feel as if the lion habitat is almost as bad as the aquarium tanks with the tigers. Mountains of cement everywhere, people elbowing others out of the way whenever a cat strolls by in boredom, and the entire site is disturbing for any animal lover. The lions can be seen from beneath them, and their enclosure is marginally better than the one for the tigers, but overall the entire experience left a bad taste in my mouth.