We left Montessori b/c we thought it was lame. The class size was large- 36 kids. My son was bored silly. With Montessoris, you have to do each "job" exactly as they want and you can't move on until you do that- even if you already know that skill.
Our local public school is really terrific, so I moved him there this year. He is writing and reading ALOT more than he did at the Montessori. He takes timed math tests in school- I am against these, but my son scored at 50% on the WJ-III achievement on the timed parts of those tests but aced the more theoretical parts that didn't require timing.
I think my son just had no experience completing tasks/tests in a timed fashion, which he gets in the public school. The montessori has no real science (it's naming the parts of the plant, not understanding the mechanism of the science), no real social studies or history.
I will say that math at a montessori is phenomenal. My son really moved ahead with that- I do Singapore math with him at home 2 grade levels above where he is, which is below him; he tested into the 5th grade on the math part of the WJ-III in first grade, but I want him to make sure he gets the basics.
