I've never stayed at the Peninsula, so can't help there. However, I did just tack a single night at the Langham on to a work trip last week. Friday night stay, booked lowest level room on Amex FHR. They were offering club rooms at a pretty hefty premium, so I would assume they are offering something, but didn't ask. Upgraded to a high floor (11) river view. Hotel only goes to floor 12, I believe. Amex FHR was a $100 breakfast credit (assume it was daily), good for the restaurant OR room service. It would not be hard to utilize the entire credit for 2 people. Also a $100 property credit, which we used to offset dinner at Travelle.

Our room was amazing, spotless, great view considering the building location and the bed/linens were top notch and incredibly comfortable.

Service was great from the bellman to the front desk to the Travelle bar (one of the bartenders brought us the wrong check, not even remotely a big deal, and another bartender comped us 2 glasses of wine because they were "training a new bartender) to the room service server. Great stay all around. We'd just come from 4 nights at the W City Center for a work event, which is a perfectly fine hotel, but it was a great contrast to see what a different level the Langham is on every front.