Came by this place because I had time to kill. Watched Mama Mia at The Mandalay so I figured this would be sort of fun. As far as admission goes, its not that bad. I mean what more can you expect for an aquarium at a casino in the desert. The Shark Reef does have a huge variety of fish including piranhas, stingrays, and of course sharks. The overall layout of the reef is pretty neat. Its done in an old Aztec theme, and as you move farther along the reef, you get deeper into the ocean, per say. The coolest part would be the final destination, the "pirate ship." There is a plethora of various fish and whatnot and its just an overall amazing look at how much water they can fit there. I'm not an avid enthusiast of aquariums, but I had a good time.
As far as time wise, it probably took about 45 min - 1 hour to breeze through it. They do give you one of those self tour phone thingys, so that helps pass the time too.