The key with any all-you-can-eat buffet is to go when they're busy. The food is fresh, hot, and it doesn't taste like it's been sitting there for an hour. Of course, some buffets taste like that all the time. River does not.
If you go to River during their busy times, you'll be pleased with the quality of their food. Lots of choices. Usually there's a carving station with ham, turkey or prime rib. Sushi bar and Hibachi service are good.
All-in-all, I like it enough I've now been there about 25 times. I started going when it was Tokyo Grill and Buffet. I really don't notice a different between then and now.
The service might be worthy of a complaint, but my bar is set so low for service these days that it's really not worth complaining about. Customer service will never be like it was. I've just come to accept that. Besides, it's a buffet. You mostly serve yourself anyway. They'll bring you silverware, seat you and (mostly) keep your drinks filled.
I would recommend River to anyone who wants an above-average all-you-can-eat Chinese Buffet. I doubt you'll be disappointed.