My DS is in his second year of Montessori school & we love it. His school goes to 6th grade (with hopes they will open a middle school/jr. high before he gets to that point).
I think no matter what school you choose for your child people will have an opinion on it. So just ignore it & do what is best for your family & child.
This is from some of the Montessori Information site:
"The name Montessori is not legally protected, and can be used by anyone, for any purpose; it is vital that anyone searching for a good Montessori school or teacher-training center be aware of this."
"THE ENVIRONMENT
The Montessori learning environment is much different than the traditional model. Instead of information passing from the teacher to the student, the teacher is skilled in putting the child in touch with the environment, and helping him learn to make intelligent choices and to carry out research in a prepared environment. The teacher then protects the student's concentration from interruption. This fosters a love of lifetime learning in the student.
Keep in mind a triangle: the student, the parent or teacher, and the environment. It is the role of the adult to prepare, and continue to prepare, the environment, to link the child to it through well-thought-out introductions to books and materials, projects, and lessons, which nurture the child's exploration and creativity. Children thus taught often surpass both the level of education of their peers, and the knowledge of the adult in all areas -- then they learn to find answers for themselves.
The Montessori school environment is arranged according to subject area -- cooking, cleaning, gardening, art, caring for animals, library corner, etc. -- children always free to move around the room instead of staying at desks. There is no limit to how long a child can work on something she has chosen. At any one time in a day all subjects -- practical work, math, language, science, history, geography, art, music, etc. -- will be being studied, at all levels, by children of mixed ages learning from each other, facilitated by careful observation, individual lessons, record keeping, and help of the teacher."
"Most experts today agree that the greatest opportunity to influence mental growth and development occurs during the first six years of life. Positive attitudes and sound learning patterns can be established when young minds are bursting with curiosity, eager for knowledge and open to change.
Conventional education relies heavily upon external motivation. Students are expected to learn specific subjects according to fixed, uniform schedules. Group instruction often requires that childhood enthusiasm be suppressed to preserve teaching plans and to maintain classroom order.
Montessori education emphasizes internal (self) motivation. The classroom is a precisely prepared environment for individual instruction and self-paced learning. Well-tested teaching techniques and materials are designed to maximize children's time in the classroom. Teachers show students how to create order and discover principles by means of carefully demonstrated lessons that can then be practiced at will.
Credentialed Montessori teachers encourage effort and monitor progress, but do not pressure their students to perform according to any preset standards or schedules. Introduction of new lessons is tailored to the individual needs and interests of each child. Discipline is mainly self-discipline. Within constructive limits, a student can work on his or her lessons at whatever pace and in whatever order he or she chooses. Independence, initiative, responsibility for making choices, and persistence in seeing tasks through to completion are qualities fostered by this approach.
The Montessori method of education has been successful for students with diverse abilities and age ranges. The Montessori method emphasizes respect for each child as a unique individual. Teachers (and parents) are viewed as guardians and protectors of the child's right to develop his or her potential in a nurturing physical and social environment. It is not surprising that Dr. Montessori was a champion of children's rights and child-welfare legislation.
In Dr. Montessori's view, children are even more important as a resource for the renewal and improvement of human civilization. She questioned the value of social reforms in adult society which did not encompass reforms in child development and education. Adults are the products of the upbringing and schooling, which she judged to be woefully neglected and inadequate. The Montessori method was thus intended not only as a pioneering effort to improve early education, but also as a crusade for general social progress.
Although our understanding of innate developmental programs in children is still very primitive, Dr. Montessori's observations did lead her to the following conclusions:
1. Children learn best by doing rather than just by watching and listening. Moreover, they enjoy repetition. Montessori exercises require physical activity and involve practicing skills.
2. Interaction with one's environment requires accurate observation and controlled responses. Montessori exercises are designed to sharpen sense perception and to refine muscular control.
3. For children, the world at large is bewildering - full of complex processes and chaotic events. Montessori schools attempt to create a simple, ordered environment in which children can focus on just a few concepts and/or operations at a time. Classroom materials are designed to eliminate distractions by emphasizing only one facet or aspect of reality. For example, to learn about "length" students are given sets of wooden rods of uniform width and color that differ only in length. Lessons are designed to build upon themselves from simple to complex, from concrete to abstract.
4. To master more difficult exercises later on, children must first learn disciplined patterns of activity. Therefore, Montessori lessons, although simple, are highly structured and precise. Each lesson consists of a series of operations that must be done in a specific sequence. (Movements are always from left to right and top to bottom, thus preparing pupils for reading, writing, and arithmetic.)
5. To exercise freedom, children must have opportunities to choose. Montessori students are given lessons involving several different sets of materials, all of which are within reach. Pupils are then left to decide how to allocate their time among the various exercises.
6. Independence is also facilitated by error control. Montessori exercises are designed to be self-correcting. When children can easily remedy their own mistakes, the emotional frustration in learning and the need for adult intrusion into the learning processes are minimized.
7. To develop persistence in students, each Montessori exercise must be carried out to completion before another is begun. The final step in each lesson is always to return classroom materials to their proper locations.
8. Children have a passion for learning, but their interests and abilities change as they mature. Dr. Montessori was able to map different "sensitive periods" in the mental development of children, during which they seem especially attracted and receptive to various subjects and skills - e.g., verbal language (ages 1½ - 3 years), writing (3½ - 4½ years) and reading (4½ - 5½ years).
9. Sensitive periods vary from one child to another and are not easily influenced by external stimuli. Attempts to accelerate learning timetables by means of rewards, punishments, or artificial exaggeration of competitive peer pressures are ineffective and may be counterproductive. Montessori schools emphasize individual, self-paced learning in a cooperative environment. Children of different ages are mixed together so that older students serve as role models or even directly assist younger pupils.
10. Montessori teachers must be sensitive to the changing needs of their students, must understand the purposes of various Montessori exercises and must then match the two appropriately. Teachers not only prepare the classroom environment and demonstrate exercises to their students; they also track each pupil's progress individually and time the introduction of new lessons accordingly.
The Montessori Model
1. Model whole child approach: values cognitive, emotional, physical, and social development.
2. Teacher is facilitator and guide; child is an active participant.
3. Child sets own learning pace.
4. Mixed age grouping.
5. Children are encouraged to help, work with, and teach each other.
6. Children have choices within the classroom and are given "freedom within limits":
Child has choices regarding work (teacher will guide, as needed, to assist student in making appropriate choices).
Child has choices regarding where to work and can move around and talk as long as others are not disturbed.
Child has choices about how long to work on specific activity or project.
Discipline is designed to develop children who are self-correcting.
Norms based on mutual respect; children involved in setting norms.
Teachers set limits and offer choices to children within the limits.
Children experience the consequences of their actions, promoting responsibility and accountability.
Children make good and poor choices; poor choices are viewed as an opportunity to develop the child's problem-solving skills."
Montessori lover here. And like any educational setting, it depends highly on the teachers. All 3 of my children attended Montessori for 3 years before going to public school. Their 3rd year was K. They did 1/2 day K at public and the other 1/2 at Montessori. I didn't find it elitist or snobbish in the least. In fact it was the opposite. The children came from all SES as well as varied races and religions. My children really enjoyed the multi-aged classrooms as well as the ability to decide the most comfortable form of learning for them. It was SO worth the money. I just wish we had Montessori through grade school near us because they would be there right now. 
