I was in J MAA-CDG a couple days ago. There was a youngish mother with two kids who were absolutely HORRIBLE. I was tempted to write a note to ask the FAs (who were being extremely nice to me as a GM; apparently the Chennai-based crews recognize even mid-tier status as something) to pass over to the mother. I have good noise-blocking headphones and mostly slept and have a pretty high tolerance for annoyance, so I didn't bother... but this was one of those cases where the kids (in ANY class, but especially in BizE on a 10hr flight) needed to be restrained.

It's pretty sad that so many parents just let their kids get away with running up and down the aisles, jumping up and down, and treating it like a playground. I will say that 90% of kids I see on airplanes are perfectly well behaved; I blame the parents and not the kids in almost all cases. (There are the cases of incessantly crying babies, but that's what babies do and not their fault.)

But as far as kids in FC in general... I'm guessing anyone who's posting on FlyerTalk is smart enough to keep their kids in line and happy at the same time. Unfortunately a lot of people are not.