I had it show up ONCE this year on my Note 4. It only worked for the first night. Fortunately I had picked up physical keys from the front desk when checking in. I've stayed in two brand new Marriotts (less than 1 year old) with contactless keycards and no mobile key there.

The fact that it uses Bluetooth scares me. Given how ham-fisted most of this stuff is, both lock manufacturers and Marriott's IT department, this won't end well at some point.