I recently stayed at the DoubleTree Richmond Downtown, and I received a full breakfast as a diamond.
In my case, this meant access to the buffet, which included items like eggs (including omelets), potatoes, bacon, sausage, biscuits, toast, fruit, cereals, and beverages.
It may have been an error on the staff's part to allow this, since the Wiki indicates continental breakfast-only, or it could be a policy change. Not sure.