We checked in at OKW at 10AM.
We had a HH 1BR booked with building requests of 12, 13 or 23(?). When we checked in, they said that we had an assigned room in building 12 that was not ready yet, OR we could take a room in building 22(?) that was also considered HH area, which was ready. Since we were headed to the parks anyways (only checked in to get our KTTW card/
DDP), we opted to wait until the room in building 12 was ready. We went to our 11am ADR at Akershus and the room was ready afterwards.
I don't know how it would have played out if we had checked in later. Would they have kept us in building 12? They could have tried to give the next person the room in building 22 and then moved them to our room if they'd asked if anything else was available....we'll never know. I guess you probably keep more options open if you check in early. At least you can "claim" a room. If you check in late, you will only be able to "pick" from rooms that are both available and unclaimed. The number of "unclaimed" rooms will go down throughout the day as people check in.
I'm sure that there is a lot more to it than this, but this is the simple logic that I employ

. We are arriving in Orlando the night before Easter. Our DVC stay starts on Easter so my dad and I will head over to AKV early Sunday morning to check in. We have a standard and a savanna view studio reserved at AKV-Jambo and we would like to be as close together as possible, preferably across the hall from each other. I think that we have the best chance of getting what we want, even if we have to wait all day to get in, if we check in as early as possible. We'll probably head over to check in and then go back and wake up the rest of the family!