I went to a Montessori school for a while. Much like what is described here. For me it was fantastic and I sometimes lightly regret not continuing in high school due to (minor) practical obstacles. That said, I believe these types of systems are definitely not for everyone. Lots of kids are probably better off with a bit of structure and imposed discipline.
Yes, there are definitely some children that this method of teaching is not suited to. Some children lack the drive to find things of interest, and according to the Montessori method, they should not be "pushed" (I use this term very broadly). At the point when they leave Montessori school, these children can be very ill-equipped in relation to their peers and "behind the curve". With some more discipline and structure, this could be avoided.
But, if you fit the right profile, its leaps and bounds ahead of mainstream education during the early years.
