It is a great hotel - we have stayed there several times. There are some things that are unique to the GCH so make sure you read the info sheet they put in your room each night - it has great info on things that are exclusive to GC guests.
They also have a "Grand Quest" everyday from 4 - 5 pm (it will be listed on the info sheet they put in your room with turn down). The Grand Quest is a scavenger hunt in the hotel. Once you have completed it, you turn in your sheet to guest services and you get a coupon for a free cookie. The first family that completes the quest, is chosen as the "Grand Family of the Day". We just did it in December and as the Grand Family you get a big balloon bouquet, a picture with the resort CMs, we got a free photo with Santa (don't know if they will substitute something else during nonholiday season) but the best part was you get the key to the Craftsman Lounge (conceirge) for that evening to enjoy the snacks and watch the Fireworks! They also switch between early entry into
Lego Store to build something and early entry into Build A Bear to build a stuffed animal.
They use to offer on the weekends, an E-ride experience especially for teens (not sure if they are still offering it so you should ask). There was an added fee, but this basically was a guided "tour" for teens with no-waits to ride 5 E-ticket attractions at both
Disneyland and California Adventure. (Tower of Terror, California Screamin', Splash Mountain, Indiana Jones Adventure and Big Thunder Mountain I believe were the featured attractions).
Also, all DLR hotel guests can enter CA 30 minutes early and ride Soarin' - that was not publicized - we just happen to notice that they were letting people in early! And don't forgot that as a DLR hotel guest, you can use Early Entry every day that it is offered. And there is a special Monorail enterance for hotel guests in Tomorrowland for the trip back if you want to ride the monrail.
It is a great hotel. They also do turn down service every night with chocolate coins. For the kids, there is storytelling in the lobby - check info sheet for times. They also offer a free tour of the GCH that hightlights the art and history of the hotel. BTW, if you are going to need a small fridge for the room, request it now. The fridge that is already in the room is a mini-bar and all the items are on sensors so if you move anything, it goes on your bill!
Have fun!