My kid have only been in Montessori program, so I can’t give you a comparison based on the same student. However, I love the Montessori method. My kid just finished his first year of Preschool at a Montessori program. Before he start, he could barely talk. After just 9 months, he’s extremely talkative now and his vocabulary is VASTLY improved compare to where he was and he’s speaking proper full sentences. His writing skill (finger control) is similar to his cousin, who is 2 years older than he is and drastically better than his cousin who’s his age. Both of those cousins were/are not in Montessori program, just your regular preschool. It’s amazing to walk into a class room of 30 3-5 years old and see them all quietly working. They seem to love to work too. When he started, his math and number recognition were better than his language. However, after 9 months, his language has drastically improved while his math and numbers have only improved somewhat. That is because he chose to do the language related work rather than the math work. After 4 years old, they’ll have a minimum requirement for what each kids have to learn before they can pick their own work. Before 4, they can pick any work they want.