Just found one I wanted to add: The Sortis hotel, in Panama, now part of the trendy Marriott Autograph collection and it appears to have a high-end kosher restaurant right in its complex! There are about 15 kosher restaurants in Panama and this one is called Kava. It's only Tier 5 so a great use of a week cert if you've got one to burn with a Flight+Hotel deal or its reasonable amount of SPG points too.
Good find. However, when going to Panama especially over shabbos you are much better off staying at the Trump hotel that is relatively cheap and right by the Shuls, restaurants and Jewish Community.
A great way I used a certificate was at the Residence in La Jolla, San Diego. It is a catagory 6 but for another 10K points per night you can get a 2 floor 2 bedroom suite with a kitchen and living room. It's a 15 minute walk to the beautiful shul and around the corner from Kosher takeout at Ralphs.
I am always looking for good values for Marriott stays as I have quite of few certificates. The Marriott vacation clubs where you can get large suites can be a great value. Please keep on posting ideas on best value of Marriott points and certificates!