London is about the last place on earth I would attempt to use my American-chain hotel points. Categories and paid rates are usually through the roof, and London is full of interesting small boutique hotels that can be had for 1/2 the price if not less. I've also done flat rentals in London when we needed room for 4+ people. (Booking.com, or I suppose these days, Airbnb)

London and Paris are two places where I take the Flyertalk-unpopular approach of ignoring the points game entirely.

Hilton just made it worse, but it was never great to begin with. 60k/nt for a basic Doubletree isn't the worst I suppose, but I'd still rather save my points for another day.