Hilton Columbia Center - Columbia SC, USA
(Stayed over weekend)
Diamonds get voucher for full breakfast in restaurant (on-site Ruth Chris), also was able to order item not on buffet from menu - I got pancakes; how quick you get that may be subject to how busy they are at the time.
Gratuity not included in voucher cost, I believe - as it was I left a tip.
Service was good, food good.