I am familiar with several Hiltons/Conrads in Asia that have identical rooms other than with view / without view, low floor / high floor. So booking a base room (low floor, no view) and then getting a high floor room with a view is technically already a "2-category upgrade." Even higher if they proudly proclaim that you've been upgraded to an Executive Room / Floor ... which is a bit pointless since diamonds have breakfast / lounge anyway ...