I have one recent data point. CY Tysons Mclean, VA has single use bottles. This is an older CY property. Need more data points before drawing a conclusion on if Marriott has reversed the policy. I was not a fan of the large shared bottles. While it most likely is more ecologically sound to have the large bottles, I didn't have enough faith in my fellow guests and housekeeping that they would truly be kept sanitary. YMMV...

--Jon