Our household noise level is pretty low, actually. The 5 year old is definitely the loudest, so I get the feeling that it will only increase.
No sibling rivalry yet, and our oldest never asked when we could take the middle child back to the hospital (which I've heard is common). We'll see.
I was an only child, and never really wanted siblings. However, I hope my kids appreciate that they won't be alone, especially dealing with us, their parents, as we age (and we're already pretty old).
Fortunately, my kids are pretty calm. I think if they weren't, we wouldn't have had three of them. They're all girls, though, so we're really in for it when they become teenagers
Alcohol-helps at first, then makes it all worse. I like to split a beer with my husband when we all get home, but yeah, there are times when there is not enough alcohol in the world...