FlyerTalk Evangelist
Join Date: Feb 2009
Location: From ORK, live LCY
Programs: BA Silver, EI Silver, HH Gold, BW Gold, ABP, Seigneur des Horaires des Mucci
Posts: 14,214
I'm not aware of ever being offered "the best room". Diamond guests get an upgrade if available as determined by the property, which may be the next category up, a room on a high floor, a corner room, a room with a better view, a suite, or something else again. For me it's nearly always been the next category up, but I have twice had suites.