Here are the perks that my family enjoys
1. Unlimted Express Pass....this is great with kids IMO
2. This trip the hour early into WWOHP....we are going to be taking advantage of this every day
3. Closeness to the parks....we love only being a 10 minute walk to the hotel to be able to take a break in the afternoon. If you stay offsite then you have that walk plus the bus/car ride back to the hotel. Staying onsite you can come back to the hotel and take a little afternoon nap before heading back out again.
4. Closeness to CityWalk. We love going over to Citywalk and having either family or adult fun. There are lots of choices for food and entertainment.
5. Pools...love the pools and they have activities througout the day for kids at all the pools. They also encourage pool hopping so you can walk or drive over to one or two of the other hotels and hang out at that pool for a change.
6. Room Charging...easier to just have your room key than to worry about having the credit card or cash, etc.
7. Package Delivery...never used it but this time with WWOHP I might just be needing that service