I felt bad threadjacking the honeymoon thread...
deburnin:
When we did the platinum plan the minimum stay was 1 night and we use the perk the day of check in to midnight the day of check out (over a 2 day span). Unfortunately there's now a 3 night minimum, which makes the plan ridiciously expensive and unaffordable. (I guess too many people gamed the system so Disney put a quash on that).
We also had an annual pass which allowed us to game the system and provided us with room discounts. We alternating room only packages with dining packages (because meal credits are good until the midnight of check out) and we save a lot of money. It did require us to check in and check out a ton (but we never switched rooms), but it also gave us tons of keycards/souvenir mugs/luggage tags. We rarely paid OOB for meals as our snack credits were sufficient to cover breakfast and lunch.
For my birthday, I got several free cupcakes and FP. I also got an upgraded room. Like deburnin said this is not a guarantee.
TIP: Also you can game the system when you make dining reservations by making your hotel reservation earlier than you want. For example, I really want to stay 9/1-9/7, but I tell them I want to stay 8/25-9/7. This moves you're 180d mark up 6 days and ensures you can get the coveted spots at CRT.