breakfast buffets are pretty much gone. I think the cosmopolitan is the only one open. The Bacchanal at Caesars does have a brunch buffet on some days.
I think Paris still does a weekend brunch buffet. But doesn't open until around 11 a.m. The price of the cosmo's is absurd, I think it's $45 for breakfast/brunch. My food credit from the FHR barely covered the buffet that morning for just myself