Austin - I am worried that my son will quickly exhaust all the activities they have to offer in his classroom. On the day I visited, even the materials the 6-year-olds were doing were right at his current level. In this moment,though, he is happy. I'll always have my eyes and ears open and always be re-evaluating. I've never been a kool-aid drinker.
I would say that many of the materials can be extended, for kids who are ready for more challenging work, thinking esp. about math materials here. If you go on youtube and just search for Montessori Math you will find some interesting stuff that shows this. A 3 yr. old can use the pink tower in one way and a 6 year old in a different way combined with brown stair to learn more advanced concepts. Same with beads chains etc. A good teacher should really be able to extend the materials to meet the kids' needs, and if needed get some more advanced stuff from the Lower Elementary class or send the kid to LE if they are ready to move up. (Even for part of the day).
If you are interested in the math stuff there is a book that explains the Montessori approach to math through elementary school. Might be worth checking out.
