If you use the DVC member cash discount, it is treated as one stay, you get keys and parking permit for the entire time. It is also treated as one stay for housekeeping. For example, I used a member discount for Saturday night, then points Sunday to Thursday nights. Our Trash & Towel was Tuesday.
If you use an AP discount, you have to check-in again and there is no guarantee you will keep the same room (although it's more than likely you will keep it). You get full housekeeping for the AP nights. We did that last year, Sunday to Thursday nights on points, Friday on AP discount. Had to go to the front desk on Friday morning for new keys and parking permit (non-member). Local calls were 75 cents that day, not the 35 cent member rate. We got a full cleaning on Friday.