my DD went to a very small Montessori nursery for 4 terms before starting school. It was very calm, the children seemed to know exactly what was required of them, and she learned a huge amount before starting school.
I think it suited her, because she's quite a reserved, contained sort of a child in some ways.
However, I can't say I was blown away by how exciting the toys and activities were. My DD is quite keen to please and keen to do things that are clearly learning activities. My DS2, for instance, would have probably kicked over the lovely unvarnished wooden blocks and run away shouting.
I think a lot of the positives in that nursery came from a very good group leader, and the fact that they had 2 staff to 8 children.
Both my boys go to a local community preschool. It's a lot bigger and noisier and more chaotic, but in terms of the quality of care, and range of stimulating things that they do, I'd rate it just as highly.
I think I'd go and look at a couple of places and see which you like best, which staff seem the best with the children, what they do with them etc and make a decision based on that rather than the educational philosophy they follow.