Hi! I'm in San Diego too.
Is the Rainbow Preschool you're asking about Rainbow Kids Integral Preschool in Mira Mesa? If so, I can give you my thoughts on it. I first investigated it as an option for my daughter when several Attachment Parenting moms I'd met at parks and activities recommended it to me. All were attachment parenting advocates and they all raved about the school. I toured it last Fall and liked it, but felt my daughter was not quite ready for separation and decided to delay admission for one year. I recently toured it again this past Fall before deciding my child would do better in a smaller, home-based attachment parenting friendly group.
Both tours of rainbow Kids Integral Preschool began around 10:30 am after a lengthy meeting with the director, Nancy Walsh, followed by a brief walk through of the classrooms, and some time observing the outside play area with my child, who was encouraged to explore and play.
What I liked about the school:
1. They were cool with the idea of me attending during her first week for part or all of the lessons so that she could adjust to my absence. I'm a stay at home mom and my daughter has never been in anyone but her parents care.
2. While not a parent cooperative, parental involvement is encouraged and welcomed more than it is in some schools.
3. They allow the kids to pursue that which interests them. It's loosely structured and child led/focused.
4. They begin the day with meditation.
5. The kids seem happy and all indicated they love the school.
6. The parents I met loved the place and recommended it fully, enthusiastically and with no reservations.
7. In general, the Director took great care to answer my questions fully--I took up more of her time than either of us anticipated and she was gracious about it.
I'm happy to share further with you via PM.