My sims were living in that big apartment in Medina Studio's in the Arts Quarter. Their neighbor Selim Benali complained about every.little.thing.
My sims were having dinner - Selim complained.
My sim had a shower - Selim complained.
My sim was painting a picture while her children were at school and her husband at work - Still Selim complained.
The most weird complaint was my sims were all asleep and still Selim knocked on the door complaining. What they can't snore THAT loud can they?
I got so fed up with him so I deleted him with manage households :lol:
On another note though, I did notice with another family if they're friendly with their neighbors, the neighbors don't complain that much.