We have one near us. I would say whether it is a good fit depends on the particular school: other kids there, philosophy of the teachers/administrators, etc. And depends if you have a child that can adapt to the system. It is a fascinating system but I think it only works well for a small subset of kids.
The mix of kids at the one near us is some who are extremely bright and then a bunch of others who just don't fit well into other systems, and perhaps a majority that are more average kids that happen to be from uschooler or homeschool families. In there are one or two who have behavioral issues that do impact the others, they might say mean things or act unfriendly and since the kids are "in charge" it's not easy for the teachers etc to limit those behaviors.
They have a core group of kids that attend as if it were a private full time school, and then also take homeschoolers on a hourly/daily basis also. So the mix of kids is in flux. A very open and welcoming community overall.
At the one near us all classes are optional. Kids are all mixed in age for all day in all the common areas. But classes are split into two main age groups, 5-9 and 9+. Some children do actually attend the classes. Many do not attend any classes and are simply there playing dress up or ping pong or whatever, which one can argue is worthwhile also. Or not. A few of the classes, especially for ages 9 and up, are reasonably rigorous. Most early elementary age kids there, being from unschooler type backgrounds, are not reading. From my perspective that less academic background limits what is taught or the expectations from the teachers for the classes that are targeted to the younger ages.
However, a few of the teachers are excellent at not being judgemental about the content or depth of what to teach and teach to all ages effectively. I would say from age 5-9 the average academic achievement is behind public schools. But then as one gets into the older kids there are more that are more interesting in terms of advanced skills.
As far as teachers, the one near me has a hodge podge of parents and paid people who teach one or two classes a week. On paper the classes all sound great but in practice there are some no one goes to. If that happens the instructor progressively dumbs it down or shortens the time to make it seem more fun. In the end some classes are great and well attended, some are more just passing the time with fun crafts, and others no one goes to so they stop existing.
Being child led, the rules and culture are defined by the core group of kids. It is a bit like lord of the flies as many of the kids are quite young. In the end the administrator guides the kids into making the rules. I feel the rules aren't much different than at perhaps some montessori schools, just more long winded and odd. It's a bit of an artifice to say the children are in charge. However, the kids do seem to personally feel a greater degree of control. The few that actually attend classes seem to be happy and motivated and are really learning things. The rest are not learning anything, but seem happy.
Is the one close by to you a full time option only? Or do they offer some or all classes to the greater community?