DoubleTree Manchester Piccadilly
Both my friend (who is Gold) and I (Gold) stayed five nights here last week. Staying in separate rooms and from DoubleTree's point of view, were separate unrelated bookings. We both were given entry to the hotel restaurant for their great buffet breakfast, every single day. At the host's check-in station, they have a list of names and room numbers, and they cross you off as you enter.
This was my experience for a two night stay back in late February of this year. In my opinion, I think the full buffet breakfast benefit has solidified here. You get it with no fuss and no hassle. And it's a great buffet spread!