It's not some mind blowing zoo with super exotic creatures pulled from deep within the Amazon. It's a small selection of large cats and some dolphins that is kind of a tribute to Siegfried and Roy. Think of it like the last impression they left here in Vegas.
As for the safety of guests, as one reviewer freaked out about: I wouldn't say it was any less safe than a regular zoo. You have to keep in mind that animals are animals and therefore they lack the cognitive ability to recognize (or care) that their crazy fueding (or peeing) may affect others. I once had a chimp throw its poop through its cage and get all over my legs. I was angry then but I didn't hold a grudge and I certainly didn't expect management to compensate me for something that is completely beyond their control. Now, if the animal escapes its cage and attacks you, you might have a case.
Anyway, I think it's great for a one-time experience.