I have this $60 off $300 offer on my US AMEX Everyday MR card.
However, another offer popped up mid-week. I'm not sure if this second offer has been mentioned by others yet. The second offer is a $100 off a $500 spend on my US AMEX PRG card, though the spend must be at UK Hilton hotels. This seemed a bit niche, but I guess it was targeted based on my having put UK spend through the card (albeit not at a Hilton, from memory). This would usually be handy but my next stay in UK Hilton Hotels (next week) will total less than $200. Maybe I'll get enough before offer expires on 31/Oct/2017.
Get a 1X $100 USD statement credit by using your enrolled Card to spend $500+ USD on room rate and room charges for your stay at Hilton properties in the UK from 6/15/17 to 10/31/17. Book direct with Hilton. Must enroll Card prior to booking. See terms.
Offer terms: OFFER TERMS
Enrollment limited. Offer only valid for eligible US Card Members for purchases made at hotels and resorts within the Hilton Portfolio in the United Kingdom. An “eligible US Card Member” is an American Express Card Member who has a US-issued American Express® Card and who receives this offer directly from American Express. Must enroll Card prior to booking and use same Card to redeem. Offer only valid for reservations made online at hilton.com, via the Hilton Honors App or by calling 1-800-HILTONS (445-8667). Excludes gift card purchases. Offer does not apply to advance purchase rates, including Advance Purchase, Save Now & Pay and Non-refundable rates. Offer only valid on room rate and room charges. Offer not valid for stays that are paid for before or after the promotion start and end dates. When you make a qualifying purchase in a foreign currency, the applicable statement credit will be credited in your local currency using the exchange rate at the date the statement credit is applied. Offer is non-transferable. Limit 1 statement credit(s) per American Express® online account. Statement credit will appear on your billing statement within 90 days after 10/31/2017, provided that American Express receives information from the merchant about your qualifying purchase. Statement credit may be reversed if qualifying purchase is cancelled. If American Express does not receive information that identifies your transaction as qualifying for the offer, you will not receive the statement credit. For example, your transaction will not qualify if it is not made directly with the merchant. In addition, in most cases, you may not receive the statement credit if your transaction is made with an electronic wallet or through a third party or if the merchant uses a mobile or wireless card reader to process it. By adding an offer to a Card, you agree that American Express may send you communications about the offer.
P.S. I also had similar offers on my UK AMEX for £50 off a £250 spend at a European Hilton, and I certainly used that offer for a series of stays in April!