Functional but room to improve
I travel 6-7 weeks per year and stay at Marriott brands frequently. When you have a wifi connection, the app does a good job. But the lack of offline functionality is annoying - its a travel app for a world-wide brand. I expect to be able to review reservations offline and have local address info accessible.
MattStQc about
Marriott Bonvoy: Book Hotels, v5.9.2