Spoiler alert, but the entire business model of hotel loyalty programs is that it costs Marriott very little to provide the benefits most of the time That doesn't make a free hotel night any less valuable to you ... it may only cost the hotel $10 if you stay at a low-end hotel where the room would have otherwise gone empty, but they were still going to charge you $150 if you didn't have the points.

The chart that has been published showing new points required in selected cities should give you an idea of what a 35K points room will get you. Obviously it will not get you a free night in central NYC or Paris, that shouldn't be any surprise. But I think most people should be able to find use in a 35K night ... surely at some point during your travels you may have need for an airport hotel room or a stay in a less expensive market somewhere. We'll better be able to judge when the full list of destination cities comes out, but I would note that in the initial sample Marriott didn't really give any examples of what hotels in less expensive markets -- say a Berlin or Chicago -- might cost, and I suspect there will be some decent hotels available for 35K or less in cities like that. The closest analogue was Mexico City, where for example the W costs 35K points per night, which would IMO be a perfectly good use of the credit card free night certificate and would easily justify the annual fee for me.

Not sure how it will work but you may have to book a multi-night stay as separate stays in order to use the certificate on one of the nights; in my experience it is never a problem to stay in the same room throughout your stay with minimal added hassle if you've done this, though it does have the one downside of making it hard to use SNAs.

(The fact that the SPG Amex is one of my oldest cards, making me want to hold onto it for credit score purposes, and the fact that Amex has changed rules on product changes and won't let you convert the SPG Amex to a no-annual-fee card any more, certainly also plays into the decision.)