I'm 18, so I never got a chance to see this when it originally came out in theaters. I've owned this movie my whole life and seen it about a million times - I practically know it by heart - but seeing it on the big screen was just enthralling! I made my parents go with me and they really enjoyed it too. I noticed things I never saw before. The details really pop out in 3D and the art is just as beautiful as ever.
There were mostly adults in the theater, but there were a couple of kids about 6 or 7 years old sitting by me who thoroughly enjoyed this too. I'm so glad that I - and a whole younger generation of kids - are finally getting to see this on the big screen!
As far as the messages go, such as the whole Stockholm-syndrome-girl-being-mistreated thing, I have to say that I never noticed or was affected by that at all when I was a kid. I wanted to be like Belle in the sense that I wanted to read and sing and wear blue like she did, but never once did I think that falling in love with some jerk and changing him was a good idea because I saw Belle do it. I definitely did not put as much stock in the storyline as a kid as adults would.
One more thing about that - around the time that I was a tween/teenager, I noticed that the Beast pretty much acts like a spoiled teenage boy. In the movie, he's about 11 years old when he turns into the beast (since it's been ten years according to Lumiere, and the rose blooms until his 21st birthday at the end of the film), and since he apparently doesn't have any parents, he's just free to be as selfish as he pleases. Viewing the Beast in that light helped me to really appreciate him more as a character, and it would probably be a good conversation point between parents and kids.
Anyway, I've always loved this movie, and I definitely think that it's worth going out to see it in 3D!