I really like the earning structure of the Green card and MR is the currency that provides me the most utility so all things being equal it would be my card of choice. The big reason I ended up moving away from the Green is the inconsistency in ability to actually earn at 3x. For dining, a number of places kept coding as "Business Services" including the cafeteria at my work campus, restaurants at MSP like the Twins Grill in concourse C, and a few local restaurants that I frequent. Parking is a category that should count towards 3x, but half the ramps in downtown Minneapolis would periodically refuse to take Amex payments.

Right now I'm using a CSR for dining and non-airfare travel, but once I've sufficiently built up my points balance my plan is to downgrade the CSR to a CSP and roll the hotel/cruise/rental car spend over to my Altitude Reserve.

VISA merchant coding has been more reliable for the places I have been using my cards.