Originally Posted by
UA-NYC
Marriott's version of it ("Based on room availability at check-in, we'll do our best to upgrade your room. Upgrades are subject to availability identified by each hotel"), is pretty weak, and similar to Hilton's.
Starwood's is much stronger ("An upgrade to best available room at check-in — including a Standard Suite.")
Yet the results are exactly the same--Starwood properties are infamous for claiming no upgradable rooms are "available", even when they're available for sale or paid upsell.