I looked into it and though it was too "loosey goosey" for me. I wanted a traditional preschool. I know others who have loved Montessori, though.
My wife and I had our daughter in there for kindergarten and we had nothing but good things to say about it. He last school before that applied similar philosophies. Kids of different age ranges socialize with one another, they learn about different cultures, they work independently, definite focus on arts, music and language and her reading skills are now comparable with second graders. Each school obviously differ in staff but what we found was that all of her teachers were great.</p>
I only know one person who went to a Montessori school; he's almost fifty and he still wears high heels and dresses.
My three children all attended Montesorri School for pre school age groups. They all went on to score some extremely high SAT scores in high school. On the other hand they are all in their mid to upper twenties now and aren't real motivated in life.
Go figure.
As a teacher, I can tell you the difference between those kids who attended pre-school as opposed to day care is night and day. The pre-school kids, whether they're naturally more advanced or their parents are more involved, usually start out in upper portion of their class and continue to maintain that higher level throughout their school years.
Something you may want to start now is investigate his future school. Make sure the principal and teachers understand his needs. Make sure they have a gifted program as it sounds like he's a likely candidate.
One thing to be very careful of, though, is to make certain that the school you pick is a real, accredited Montessori institution with trained teachers. Apparently there are schools out there that use the name but have no affiliation with either of the two large organizations and who do not hire trained instructors.
My only advice is that you pay as much attention to the development of virtue and wisdom as you do to the development of knowledge. Brains without wisdom just makes you a very clever, arrogant idiot. (Watch Charlie Rose for a week and see what I mean.)
My son went to Montessori until 3rd grade. He loved it! I loved it! It was fantastic! When he went to public school, he really had a head start. He is now almost done with college... I think Montessori really helped him to learn to think critically. He is very logical. His environment at home helped too, but I think Montessori was a large part of it. He was fortunate enough to have one of Maria Montessoris' proteges as a teacher.