Not sure it’d be considered “high end” but nice full service Marriotts in urban locations can have good points rates sometimes and can be a nice sweet spot for redemptions. This year I’ve stayed at the Downtown Manhattan Marriott near the World Trade Center in the 35k range and the San Francisco Union Square Marriott in the 45k range with use of certificates. (The New York Marriott had $400+ cash rates for those dates too, so it was a rare good deal in the age of dynamic points pricing!). Caveat that it’s easier if you’re flexible on your travel dates though