TRAVELSIG is right. The President stays at the Warldorf for security reasons: underground garage and, indeed, private train station that allows for quick, secret departures and arrivals. In Singapore, the major US diplomats and delegations stay at the Shangri-La because one of the wings (Valley?) has good security infrastructure. Since I'm not quite as worried about that personally, I don't use it as a guide for where I should stay. By the same token, with Royals, you might have the bounds of history dictacting where to stay. Except in Harry's case--- and I'd have thought MBS, not a W for him.