I've only recently gotten the Discover University pack and finally got some roommates (ad never did work). But I have 4 roommates because I went out and actively worked to get them. Here is the breakdown so far:
Pranav Banerjee:
Pros:
Sleeps at night in bed
Cleans up
Cons:
Bakes cake after cake after cake after... well you get the picture
Habits:
None so far
Mario De Santa:
Pros:
None noticed yet
Cons:
Does not sleep in his bed (but at least leaves the lot and comes back apparently well rested and in high spirits)
Habits:
Watches TV
Akira Kibo
Pros:
None noticed yet
Cons:
Naps on couch instead of sleeping in bed
Will not bathe (but sometimes uses the hot tub)
Doesn't leave the house mostly
Habits:
Watches TV sometimes
Uses the hot tub sometimes
Matthew Gossett
Pros:
None noticed yet
Cons:
Always sad, I mean ALWAYS SAD
Never bathes
Doesn't sleep in bed
Naps in hot tub
Habits:
Uses the hot tub sometimes
Leaves the house sometimes
To be fair, I don't really have much in the way of entertainment and it's early spring so too cold for the pool. So TV and hot tub really are the only entertainment at the moment. I have an entry level job and $13k in weekly bills so can't afford to put in a stereo or anything else until I get a house full of roommates.
EDIT: Just checked on Matthew and he was napping in the hot tub. Added that to cons.
Also, I wonder if they prefer single beds or double beds? I have doubles for all of them but only one ever uses his.