I enjoyed the buffet. Now, I was comped all my meals here, so given that they were "free", I don't think I would pay $20 rather than head to a restaurant for that price.
This place is right next to the sports book towards the back end of the hotel. I am not huge on buffets, so I don't really have much to compare as far as Vegas hotel buffet's go, but I would guess this would have what you would expect at a decent buffet. Without getting into specifics, I don't think most people come specifically for the buffet at the Hilton. You are either staying here and don't feel like going anywhere or...no, you are staying here if you are eating at their buffet.
PS: I broke their cardinal rule of not taking food from the buffet. I stole a couple cookies...thank you Hilton Buffet.