At least you still don't need an existing reservation to do a BRG. Any other chains allow that? (Looks like SPG does. Dunno about others, but I'm sure some don't.)
Nothing more annoying than only one room of a particular type left, with a lower price elsewhere. So you book it to do a BRG, but then since it was the last room, the room disappears from the competing site and no BRG is possible.