Kids that age should love it! It a VERY high engery show with lots of sounds and colors. They even had a part of the show were they had three kids come up to the stage. I don't know of that part was replaced or not during the recent rehab though.
It does feature some "adult" humor, but it is masked just like any good animated kids movie where it flys over kids heads and parents will be laughing. The only part that is not 100% kid friendly is the end when they tell everybody to stand up and shake your butt and then they go into about a 3-4 minute insane (where talking crazy lights, GIANT coloring changing beach balls released into the crowd, toilet paper, everything that Blue Man is known for and what makes them great) segment where the song that is playing is basically tons of insane things you can call your butt...leaving off some like the one that starts with A.
Here is a clip from the ending of the show that shows you what the ending is like. Be warned, it is the full ending of the show so it will spoil it for you. I suggest not watching it with the kids so they will be totally surprised at all the stuff that is happening around them. (I am not sure if
Youtube videos can be posted here, if not, please remove it, thanks)
http://www.youtube.com/watch?v=gZKSU0LQtRg
With La Nouba being twice as much, I really would stick with Blue Man. While it is not as big of production as La Nouba, it is still well worth the money. Last summer was our first time ever seeing the Blue Man Group and we only did it because of the cheap tickets I was able to get being a college student. When the show was over we all agreed that 1) Why had we not gone to this show sooner? 2) Even without discounted tickets, we would go see them again in a heartbeat and 3) When can we see them again? We still had 3 days left at Universal after we saw them and we almost went again on the last night because of how much fun we had.