A disposable has been known to show up on Jenna's bum when my mother is here. Until I finally decided to not buy them any more and force my mother to learn the system.
As for nighttime, I think we used one in the last couple of weeks... because laundry wasn't done in time.
I don't like the ammonia smell in the morning, either.. but I find I don't run into that with certain systems. Joeys and prefolds, yes. Mini Rumpsters and Joeys, no. Weird, huh?