Sounds like you've already decided on the GC. I support that choice, but there are reasons to choose the DLH. It's less expensive, the Neverland Pool may be preferred by some kids (but I think GC may be able to pool hop to DLH, but not visa versa), the rooms are a little bigger, and some may find it a little more festive. But I would choose the GC for it's location and style.
An advantage of booking through AAA is the multi-Fastpass option, only available through AAA when you are staying at a Disney resort. This can be a great benefit, but in October isn't worth as much. If you were staying longer, you might also be able to get your 4th night free. One last thought; if you are able to book without a cancellation penalty, you might find the rates drop a couple of weeks prior to your trip if the resort is underbooked. It's pretty dangerous to count on that, but is nice to watch for if you are able to cancel and re-book.
PS -- watch out for the total rate when comparison shopping. You need to add tax and resort fees to some of the published rates while some published rates will include the tax and/or resort fees.