As for Pros and Cons, not everybody accept the Montessori way. Dr. Montessori have mix age classroom. Children have lots of educational material to work with. They could select what they like to do first or last. They are given freedom to choose within certain big guidelines. But what comes with this Freedom and Choices are - responsiblities. So as we let them make their own decision, along we must teach them their responsibilties. So at early age, you could already see children in a Montessori classroom help setting the table, mopping the floor. They help out and they tidy up after themselves. Making responsible decision for themselves, classroom is extremely orderly most of the time.
Some people say that it will be hard for Montessori chidlren to fit in regualr classes. One main reason is : They sometimes get bored waiting for the teachers to assigne them things to do.
Depends how you see things, at some ocaasion, a parent might find a child with "no discipline", while another parent might think the child is perfectly reasonable with disciplined.
The thing that I like about Montessori teaching is because it is a more holistic approach to teaching. She does not focus on say flash card alone, or phonics alone. She pays attention to a balanced overall developement of a child. she cares about the personalities and who the child will become tomorrow.
Since I have used the Montessori method on my son, he has major improvement. He used to rely on the nanny to do quite a lot of things, and now he starts acting more responsibly. At the age of 5 1/2, he is fluent in Madarin, English and Cantonese. He has mastered at least 6 digits of mutiplication, subtrations carrying the digits over. And I never dream of he could master and actually undesrtand the definition of terms like" percipitation, condensation, percolation". I didn't have to force him, I only let him play some matching games. Whatever you do with them, have with lots and lots of patience. You know that once you get them going, you can't even stop them.
Of course, my sons still has tons of areas that he needs to work on, but unlike before where I don't even know where to start and how to start, I now learned to pay more attention to observe him and leanred how I could motivate and encourage him to move ahead.