The real difference between to two resorts to me is this, Disneyland is truly Walt's park. It was the first realization of his dream to build a park and he was there for the first eleven years it was open. I know it'll sound crazy but I prefer Disneyland due to the "spirit of Walt" that seems present there rather than in WDW.
NOT discounting WDW, I may live in Los Angeles now, but I grew up in Atlanta - so my first park experiences were at WDW.
Getting back to this - there's a guided tour offered related to that called "A Walk in Walt's Footsteps", it's about a four hour tour which I realize might be difficult with the little ones, but it's something to think about. You get to "meet" one of the puppets in the Enchanted Tiki Room after the show and go into the lobby of Club 33.
I did this tour with my boyfriend a few months ago and we're park regulars and APs that go once a week and we thought it was spectacular.
You mentioned that you'll be staying at the GCH - AWESOME! This is my favorite hotel of the 3 Disney hotels. We stay there regularly, you'll find the entrance into DCA quite useful, and it'll let you into the park right at the FastPast distribution for World of Color - I recommend trying to get Blue seating, it'll put you up front.
I think you'll find that the DL experience is a little less chaotic that WDW, in terms of people.
When in August are you going? End of August is best because school is back in session in the states and you go back down to the "Stroller" pass people during the week days. Those are the days to do the really busy attractions Tues-Thurs. We went on a Wednesday the first week that school was back this year and walked onto Space Mountain 3 times.
Hope some of that was helpful!