We don't have one primary host. We sorta break the day into the ever-fun "Who likes to do (x)".
Like, Lola or Linn go to work usually (occasionally me), and Linn or D cooks, HB cleans (and screams the whole time - poor roommates), school is Leon (sciences/math) or me (music/language) or ell (art/music/latin/writing/history) depending on the classes, Gemini or me or Lola like to do exercise/outside activities, and then free time is kinda split between lots of people. We've never had one primary host, it seems. it works best for us this way.
During the day, we also kinda help each other out and make comments. Linn and D will mention this or that spice or recipes and cook together, and Minnie helps HB organize, or Linn or D will help Lola at work if something needs to be done creatively since she has *no attention to detail* and Linn does/is great with colors, and D has insane spatial reasoning for what looks intriguing. rinZU makes either really annoying or zen comments to all of us if we're stressing. at school we'll chat over essays/assignments and there is usually at least 2 people taking notes at any given time (which gets some weird looks, writing with both hands at once). and getting dressed in the morning, EVERYONE is involved in.

actually, in anything, there are usually a few of us around. :p
it works well for us. even though it's sorta a buddy-system-revolving-door kinda operation.