The unschooling group is a bit less supportive and a bit more judgemental. I think the major problem with that group is that it includes a lot of schooling home educators who mistakenly think that home education is equivalent to unschooling. It isn't. That leads to some pretty heated debates in the group.
Home educators may be unschoolers, but I know quite a lot who teach their children to a curriculum who could not be described as unschoolers. If you try to teach your children then you are probably not an unschooler. The difficulty for parents who try to teach is that you are necessarily limited by your knowledge and facility with the subject, and you may be sure that any gaps in your knowledge or lack of confidence will transmit to the child.
The whole point of unschooling is that once you put the child's curiosity and interest at the heart of the enterprise you are no longer limited by your ability to teach them, but by their ability to ask questions and understand the answers. When you make their interest the driving factor instead of your own knowledge then you put them in charge of the journey - then your job is to facilitate the search for answers, NOT to have all the answers.
If this seems like the same thing to you, you haven't understood the difference. There is an extreme difference in the dynamics of the relationship, which means that your child's interests are pulling them in the direction they need to go, instead of the parent pushing them there.
The best way I have ever heard it described, is that schooling is the filling of a bucket, while unschooling is the lighting of a fire.