There's really no advantage of Diamond over Platinum for me, considering I can't use my SNUs. Most of my nights are for business, so there's no point getting a Suite when I'm travelling for work. I was going to use the SNUs to give my wife a little treat but all my holiday travel next year is in Italy.
Even if IHG is earn and burn, I'm not fussed about not being able to get a room at a Raffles or Sofitel Legend. Intercontinental is fine with me.