Yes, most of the prop will arrange early checkin if possible. This week I checked into a SHS that had been full the previous night, and they had my room ready by 9:30AM.

Once I was checking in to the Marriott Park City, and called them from the car a few times to tell them I had a sick child and would REALLY like an early checkin. When I arrived 9AM, they gave me the only room they had available, which was a special room for handicapped guests.