I've seen several Cirque shows and I did not like La Nouba at all! I guess it was just too avant garde for me. I also thought it was too serious and parts were kind of militaristic (not festive at all, IMO). I did not take my son (who was 5 1/2 at the time), and I am so glad I didn't spend even more money on his ticket. I did go with my sister, who had seen it before, and she said the performance we saw was not as good as when she went previously (I guess performers/acts do change to a certain extent). It didn't help that we had an entire row of guests behind us who talked, loudly and in Russian, during the entire show.
We just saw BMG this past Nov and I thought it was fantastic! My son (now 10) loved it as well! I would not hesitate to see BMG again, and I thought it was completely appropriate/funny/irreverent for a 10 year old boy. I especially loved that the BMG performers were out in the lobby after the show and posed for pictures. There was also great audience participation and spontaneity in the show we saw.
I have seen other Cirque shoes that I enjoyed, but I would not pay to see La Nouba again.