You didn't say the ages of your kids but mine are 5, 6 and 10 and they LOVE the AS Movies! It is one of their favorite places to stay.
now, here is an adult view...I personally love the theming also, it's a very cute resort and the movie stuff is cool. The food court has a fairly wide selection of food and the Fantasia pool is really nice with Sorcerer Mickey! I would not hesitate to stay there if there were only two or three of us and we weren't going for too long.
But...
1. the rooms are dinky...depending on how many of you there are and how much stuff you are taking, you may feel cramped. My DH hates the AllStars for this very reason.
2. My main dislike is the lack of soundproofing...we stayed at ASSports in June and could hear every toilet in the building flush (at least it seemed like that when we were trying to sleep) and could often hear our neighbors who were up later than us every night! The noise didn't bother my kids too much but it did keep me awake some. We were on the 2nd floor so I guess we got toilets from both above and below, asking to be on the top floor might help cut down on that some.
3. One other minor drawback is that Movies is the last bus stop, which means that when you get on in the morning the bus is already full and when you get on in the evening to go back to the resort, you are the last ones to get off.
However, if it was a choice of staying at Movies or no trip to Disney, I would choose the Movies in a heartbeat!
I hope this helps, I really do love the theming at this resort but thought you needed to hear some cons also so you could make an informed decision.