From my experience, it highly depends on the property and even at the same property, there are sometimes big differences in regard to upgrades or special benefits.

As a very small data point, it seems, that Asian properties tend to be more generous in regard to upgrades than US or European properties. The CP Bangkok Lumpini Park has been very generous and upgrade me to Club Floor while the CP at Heathrow does not offer anything special than the booked room as IHG Platinum (which was at this time the highest status). CP Brussels Palace offered an upgrade on one category while they were fully booked, but nothing during other occasions and so did the CP Kensington.