What Alegna said.
If baby is up at 5, I am up at 5, if baby wakes up just as I am going to bed, then I am up until she goes back to sleep again. She is generally a good sleeper (Goes to sleep at 5-6pm, has a couple of night time feeds and wakes up at 5-6 am), however, there are occasions when she gets a bit head crazy and starts waking up at all different hours and not sleeping etc.
Sometimes I have found, that for whatever reason, there are some nights she will go to sleep fine and then wake up within a couple of hours SCREAMING, nothing I do stops it, but she calms down eventually and goes back to sleep.
Sometimes, she simply will not go to sleep and is just screaming and I simply have to keep thinking about what will work whether it is rocking, breastfeeding etc or simply holding her while she cries. She is very mobile (nearly 8 months and cruising) and she wants to be up and doing everything her sisters are doing or just up and into everything.
I coslept with my eldest 2, no CIO, responded to every time they cried during the night and I have no problems with them at night time. DD2 can be awke until 9pm (they go up at 6pm for story time, snack and bed time drink, 7pm is lights out) but she doesn't come down stairs, she just stays up there and fiddles, looks at a book etc. If DD1 is awake longer than usual then they will often just talk to each other and if either wants anything, they just call down to us. I have been over friends houses and the kids are constantly up and down the stairs, shouting, screaming etc and those kids were brought up with CIO and no co sleeping (cos CIO is so great and really works and cosleeping is so bad and creating a rod for your own back lol).
People are ALWAYS amazed by our daughters night time behaviour, unless baby is being a bit off, we generally, from 7pm have an incredibly quiet house, the important thing though, is there was no trauma involved for the children or us, it was just gentleness that got us here and a desire for night times to be comfortable for both children and adults.