Just to clarify the package delivery, anything you buy will be delivered by 7:00 a.m. the next day to the bell station at the hotel (whichever onsite one you are staying at). As far as I know they will not bring them to your room directly. Its nice but for kids especially they don't usually want to wait until the next morning to have what they bought!
You also have charging privilidges. They give you a card (not your room key like the WDW onsite resorts) that is hooked to the credit card you give them and that way you can charge anything at the shops and restaurants inside the parks, World of Disney and any Disney owned restaurants at the hotels. It can be very convenient and very deadly!
Then of course as everyone says, the Disney touches, great customer service and the fact that you are staying at a hotel vs. a motel. Most of the places right near DL are motels. So at the DLH, PP or GCH, you have interior hallways, room service, full service restaurants, valet and bell services, health club access, newspaper delivery (M-F)m valet parking, laundry/dry cleaning services, bars/lounges, and probably some other things I am probably forgetting!