I've had the following experience a couple times: Knowing that I'd be checking out late the next day, when I check in, I ask if I can keep the room until, let's say, 2:00pm. The desk clerk initially says something like, "You'll need to call down to the desk in the morning. Oh, wait, your Plat. I'll be able to arrange that."

This leads me to believe that at many properties, the guy off the street is held at bay so the Plat/Gold/Silver Rewards Member has an opportunity to be given the late check-out first.

Although this does not allow you to compare what you are getting to what someone else is getting, it does show some effort at giving MR members with status some priority.