i've had similar Club upgrade experiences at London City, and at Shoreditch (after a push) as Plat, although after today's reward devaluation i fear i will be resorting to pointbreaks as my only PC activity in future.

however, the comment by 'sdsearch' about HI upgrades intrigues me (as i have aggresively avoided that brand for the lack of stated Plat benefits) - does the research you mention involve contacting each hotel separately to confirm their Plat policy (which i am happy to do) or is there a master list around that would save some of the leg work?