I have rarely had any problems with small children in J. The UM sitting next to me recently was quiet, played with his laptop, and was very polite. Don't think this is a problem at all. Someone mentioned airlines banning small children from F- I am not aware of this. Anyone know of an airline who does this?
The WORST passengers I have had sitting next to me are all adults who drink too much and bug the FAs constantly for no good reason.