I usually have a 8 Sim household, very rarely do I keep smaller families.
It can get annoying, especially when you are trying to focus, another one can be having a meltdown.
I do keep autonomy on for my Sims, so they can take care of themselves, but sometimes I have to cancel an action that they do.
For me, I have had 6 teens and two adults, the teens can be annoying when they are having their mood swings. Some families are 4 adults and 4 teens, and others vary from there.
Also, prepare to download a house of 8 Sims households, because the houses available can't really handle them unless you use cheats.
Another thing is you have to keep track of what the Sims need to do, for schools and careers, because they may always do the stuff they need to do with autonomy on.
