Thanks polarbear, here are a few answers:

We live close enough to Seattle for weekend trips but too far for everyday school and work. We really don't have many options in our area except the two mentioned and a few very religious private schools.

I agree that if he stays or moves we need to implement more advanced more independent accommodations. Perhaps requesting AT help though the public school will be a good step so his current needs can be assessed.

His writing issues are not just dysgraphia based. He also has a genetic disorder that makes writing difficult. His wrists and fingers are extremely hypermobile. I am going to check with the doctor about what services are available through the children's hospital. When he was first diagnosed, he met with an OT and was fitted for a cool bike with training wheels. That was all done through the children's hospital so maybe they do AT type evaluations too. What's the breakdown on determining when something is medical versus educational? Maybe with the medical documentation we could avoid getting bogged down in RTI.

I also remembered we are friends with one of the middle school special education teachers. So if DS ends up staying with the Montessori, our friend would probably be happy to tutor DS to help make sure he is middle school ready with the AT if it seems like the Montessori is not implementing it well.

Ugh. Lots to consider.

As to why people are leaving...

There aren't a lot of people in the private school market here. Most people are reasonably satisfied with the public schools. And those that aren't, want Christian based education. This school is secular.

When kids that have been in it leave, it is usually because the family can't afford to have all their kids in it. Some leave when the gifted program starts (third grade), or when elementary ends and middle school begins.