Thanks everybody, from that I can conclude that a rollover is unlikely, ie I will have to reach 100k. My stays are habitually infrequent and high value so more stays is not an option. A 'mattress run' might be, but frankly life is too short to stay in hotels unnecessarily, no matter how pleasant Hilton make the occasion. In any case, my itinerary for next year looks less crowded than usual so the £330 or so may not be a solid investment.

The benefit gap between Gold and Diamond isn't that great, the main benefit being the executive lounge with the occasional upgrade welcome.

Gold isn't exactly slumming it....