Montessori schools

We are considering moving EV to a montessori school.  We have loved Mount Pisgah and how they have nurtured and taught EV over the last two years, but we feel that she may have outgrown the school.  It's funny because the very thing I have been critical of Montessori schools is exactly what EV needs right now.  I was critical of how Montessori programs are focused on letting kids decide what they want/need to do.  The biggest factor is by being in a classroom with kids her age and having an age-centered curriculum, it feels like she is being held back.  Since she does everything well, she gets overlooked and is never challenged. 

Another thing I really like about a Montessori school is that the classroom has a mix of ages (2-6 years old).  One of EV's closest friend goes to a Montessori school and she is almost 5 years old.  Even though they are 1.5 years apart, they get along great.  But what I am also so impressed by is how much EV is challenged by her and learns from her.  For example, EV loves being outside and is very active, but she has been afraid of the monkey bars.  She would just hang off the first bar, lift her legs up to the bar, and be done with it.  She was too afraid to try moving from one bar to the next.  Well, last weekend, her friend glides across the monkey bars, and the next thing I know, I see EV trying to do the same.  She overcame her fear and at least tried it.  The idea of a mixed age class is more and more appealing to me--it will teach her to be a good example to the younger ones and challenge her to do things outside her comfort zone like the older ones.

I really struggle between pushing EV and letting her be a kid.  I feel like I was forced to grow up too fast and I don't want that for EV.  I want her to enjoy being a kid but at the same time I want her to be challenged.  We think this is the right move for her, she loves school, she loves being around other kids, and she loves learning.  We just want her to be in the right environment that can nuture these things and allow her to reach her greatest potential.

Do you have any experience with Montessori schools?  I would love to hear them!!