As with everything, there's bound to be differing opinions. Personally, it's been a great experience so far. I think they can benefit from doing something like learning party dynamics, where each person has a job, and the group rely's on them to do that job, or else everyone fails. That alone can apply to group projects in school quite easily. Sure there's a chance of encountering situations that might be difficult to explain, but you encounter the same thing outside the home as well, be it at the mall, supermarket, or just about anywhere you go. And every solution doesn't work for everyone, but this is working quite well for us.