My son had a negative Montessori preschool experience.

Here is an example of a type of problem he had:

The pink tower is a common Montessori material. It is a set of ten blocks that increase in height from 1-10 cm. Each block had to be carried individually from shelf to floor mat. After ten trips, there were two acceptable ways to do the work - arranged horizontally in order or vertically in order. They would then need to be returned one at a time.

My son would want to make a snowfamily with a dad, mom, boy and baby snowball. He'd want to serve them food on dishes from another work, use dry beans and rice as the food from other works and finally he'd want to include a few other kids in this plan.

This was all very bad.

First, the works have specific ways they are to be used because they are teaching specific things. This also means they can't be mixed. Working with another kid wasn't allowed unless the work was specifically designed as a two kid work.

So for him it wasn't a good fit at preschool.

Now that he is older, it is a lot better.