The quantity of the Paradise Buffet is the same as the others in Vegas, just the quality doesn't live up.
We went there for Brunch. Standard stations along with an Asian Station and a chocolate fountain at the dessert bar. The food overall was mediocre. The salad bar was decent, and everyone knows that is a cardinal rule about buffets - no salad bar to fill up on. But there wasn't anything else remotely exciting for me to fill up on. The breakfast station was pretty empty everytime I went up, they weren't refilling it fresh. And the buffet itself wasn't even crodwed. There were a ton of weddings in there - either pre or post parties. I can't remember if the mimosas were included or additional, but it was a pain to try to get them refilled. We joked with our server to just leave the bottle so she wouldn't have to keep getting flagged down and she looked mortified.
Eh - go to Spice Market or Rio if you want a good buffet.