I stayed at the Rio multiple days for a conference and found that this was a tasty and refreshing change after eating at their All-American Bar and Grille one time too many. Don't get me wrong the Grille's food was good, but the thought of eating another burger was nauseating.
The food at KJ is authentically Chinese and they serve a good variety as any restaurant in the San Gabriel Valley. The couple times I ate here was for lunch and dinner so I didn't get any dim sum, but the quality and tastiness really hit the spot for someone who grew up on Chinese food. There are also favorites that are suitable for others that are not too familiar with Chinese food. I recommend the Beef Chow Fun and Won Ton Noodle soup. They even accommodated my dining partner who was allergic to some ingredients, when requested to not add any sauce to a shrimp dish and to simply steam it they complied.
The only reason why this place is not getting a 5 star is because of the price of their dishes. Everything else service, decor and food is up-there. I know there are many options to dining in Vegas, but not for Chinese so maybe that's why this place can profit from increased prices.