Hi Ephie,
I think this is a timely question, especially as I just about lost my mind trying to make dinner for us earlier.I like Time-In and I also find that, much like any one technique of discipline, it's effective to have it in the parenting toolbox.
I think that there's a damaging misconception that Time-In is a nonstop empathetic festival of permissive parenting; that there's a lot of talking and negotiating. In fact, I find it to be an aspect of smart, more effective guidance technique, because we have to be detectives to best address children's acting out. Our children's less desirable behaviors don't usually exist in a vacuum, and I find it useful to ask questions before deciding what sort of discipline I want to use. Because, if we think about it, we generally see patterns in our child's behaviors--some acting out may be related to tiredness, or to vying for attention, or hunger--and sometimes, just plain contraryness, which even the most wonderful and magical parents of parents are going to have to deal with.
Time-In centers us in the idea that children often have needs they don't understand how to express verbally, easily. It's also implied that if needs aren't being met, we try to meet them in a calm, non-punitive way. Feeding a hungry child, who really blew it and hurt another child, gives him room and space to get his head clear (and stomach full) before returning to make amends particular to the situation. A child making a mess can help clean it up when they are in a better mood to cooperate, and can learn why their actions weren't helpful.
It's also true that I find that different degrees of "taking a break" are involved. Certainly, feeding a child or finding them a place to be alone and look at a book can help. And then, sometimes it won't. Sometimes, taking a break is really of no use because "Kiddo" is flexing their personality and just going to be disagreeable. I think it's important to know ourselves as parents and where our limits are. Parenting is not one long altruism parade; we all have our limits of what it feels good for us to be flexible on, and sometimes our sending our kid to their room is less about our being inflexible, and more about being at one's breaking point. I love a lot of positive discipine books, but do take umbrage with the notion that being sent to one's room (not full-on grounding, by the way) is the worst thing in the world for a child when you've reached this situation.
I also help the children I work with to find a quiet pace to sit until they are ready to come back and remedy a situation they aren't cooperating on. Sometimes it's something as simple as "I need you to sit in this chair until you are ready to keep your hands to yourself." Some kids get the message and pop right up, while others will sit alone for quite a while. This is also another opportunity to take the breaks they didn't know they needed. The big diffence with between this and Time Out is that the child is free to come back when they can cooperate, and that the behavior isn't addressed to the child until they are ready to come back.
These are the techniques that work for me. I also highly recommend "How to Talk so Kids Will Listen and How to Listen so Kids Will Talk" by Faber and Mazlish. If you haven't read it, this book has great tools for doing the detective work involved in finding out why our children are doing what they're doing. It's definitely a great foundation book for me. Great question!