I have cleaned rooms too, and am very familiar with the metrics at hotels. I know a lot of the fancier, big union operated hotels have near 20min standards for their housekeepers to meet, but they pay very well and have more young, healthy housekeepers. And have redundancies that can take care of the trashed rooms that pop up.

On the other hand, there are lots of motels and franchised hotel operators trying to squeeze 20min per room from housekeepers at low pay, and I would not believe they can keep that pace up and delivery a quality product for 13+ hours in a day.