I have a cockatiel.
We all love him and he is very friendly.
However, cockatiels are 'flock' bird who call to the flock when they are out of sight. We are his 'flock'
We get (loud)excited greeting calls as soon as we walk into sight. Or even if he sees our car pull into the driveway.
We get (loud) alarm calls when other people aproach the house, when the birds outside are alarmed, when the dog barks, when a storm is approaching etc. (Different calls)
We get (loud) annoying noises (imitates phone ringing, imitates squeaky toy, bangs side of cage) if bored and wanting attention.
Some of these we find endearing, some we find amusing, some a little embarassing (he wolf whistles anyone leaving the bathroom as he can see the door), some are just plain annoying.
Not a good option for a roomate situation unless they also want a cockatiel.