I don't enjoy most buffets in the US, even including some expensive ones I've tried in Vegas. OTOH, I thoroughly enjoyed a Sunday Jazz Brunch at Zinc in Prague and always go to the Friday brunch at Mina A'Salam when in Dubai. The Sunday buffet at the Hilton Beverley Circa55 restaurant comes closest for me in the US if you can get a table outside on a beautiful California day.

Apart from the food quality issues, I think the difference is those mentioned are meant to be spread out over at least three to four hours. Your table is your table for the afternoon. You take the papers, or your book, or the family and have a leisurely afternoon. I can eat about six small plates (side plate size) and tend to go for one theme on each plate - rather than a bit of this and a bit of that. At Mina you can wander around "The Wharf" outdoor cooking/grill stations, get freshly cooked dim sum, cocktails mixed, as well as the other dishes laid out inside Al Muna.

Its a bit like the difference in UK drinking culture and the rest of Europe, although I acknowledge in advance that's a generalisation. We tend to do vertical drinking (or our young people do) wheras there is a more cafe culture in France, etc. US buffets do seem to be more about how much food how quickly for how little rather than an extended social occasion.

And I agree about "Chinese buffets" - my home town is over run by them and they are universally disgusting.