Marriott Platinum does help for late check out, but it is definitely not a given at the Time Share properties. And nothing like the 4 PM late check outs sometimes given at Marriott when they are not full (probably due to extensive house keeping for the bigger units and high occupancy rates). We have only gotten a late check out twice -once when we were changing rooms at the same property (and we told them we didn't want our perishables to defrost) and once when a friend of ours somehow managed to talk the front desk into a 1 PM check out - basically unheard of - and we have no idea how she did it to this day?????
We have been told everything from request a late check out (one hour only) the night before to request it the morning of to request it when you first check in...............no matter what we do - we generally hear that all of the late check outs have been given out. Don't know who it is that gets these since Marriott owners should really have first priority - in my humble opinion. Our experience is the knocks from house keeping usually start at 9 AM and continue until the 10 AM check out - an annoyance since the front desk should alert housekeeping when someone has checked out so they don't have to keep banging on doors.
We have overheard owners at the front desk very annoyed because they can't get in 3 or 4 hours early - Marriott does not guarantee anything before 4 PM - but it seems like the priority is getting people in early over letting someone stay an hour or so late.
Anyway, that is our experience.