Generally for most cats indivdual feedings are best.

But it can depend on the individual cat. All 3 of mine get fat if i let them free feed. And most cats I have owned, have also been this way.

Though it is a convincence, I keep one around incase I have to leave for a night or so, so they can have a constant food supply if I can't get someone to come over and feed them when I need them to.