The main difference was how much more challenging Montessori education was. The teachers really observed me and how I performed on assignments, and they could tell when I needed more of a challenge, and assign something to me that was just at the edge of what I was able to do. In the traditional education, if I consistently just did the bare minimum expected of everyone, I was a double-plus A plus student.
I was also allowed to explore subjects that interested me in greater depth, as long as it didn't come at the expense of subjects I found less interesting. I learned a lot of English and maths in the first few years!
If I had a disagreement with a Montessori teacher, we would sit down together and have a mature conversation about it and reach some sort of mutually beneficial solution (yes, even when I was under the age of 10!) In the more traditional education, there was the assumption that if I disagreed with the teacher, I was wrong and should shut up. (I ended up not passing a few classes in the traditional school because of disagreements with the teacher – I simply stopped attending the class at that point. Didn't seem productive to go on.)
I also had a lot more spare time in the Montessori school. As long as I did well on the work assigned to me and didn't bother my classmates, the teachers didn't really care how I spent my time. I could sit in a corner and read or do long multiplication, or go out and kick around a soccer ball. I would like to think this helped me learn independence.
On the other hand, I also have a notable lack of respect for authority figures. I like to think this is good, but it has also gotten me into trouble for disagreeing with hardline managers, refusing to do things I think are unethical, etc. I think some of this can be attributed to the Montessori school, where respect was based on fact, rational argument, and patient listening, rather than who should be commanding whom.