We don't have them in Iowa, but I always remember the cultural reference to them.
Iowa has Golden Corral, Bonanza and Sirloin Stockade (aka Bum Steer). I don't ever remember any of them having quality food, but they were a cheap all you can eat extended salad bar.
When I was in elementary school, maybe into high school, there was a Bonanza not far from us - and it was GOOD. I mean, REALLY good. But eventually they changed and the price went up as the quality went down, and of course it closed. Ate at a Sirloin Stockade once in Iowa . . . and it was OK. Couple of years later we tried one in Austin, TX - and after one bite each of us spit the food into our napkins and we got up and left, never to return.
As for buffets . . . there was a really good "smorgasbord" buffet just outside of Chicago when I was in school called House of Norway. We went there a lot - it was so good that in high school sometimes we went there before or after a movie on date night, and nobody complained. Everyone liked it. But it changed, lost business, and eventually closed.