My city has both Immersion and Montessori public school programs. I put DS in the lottery for both types of schools and then sat and though about them until the drawing.
I liked the idea of Immersion for him because I thought that being able to learn another language would give him something else to focus on. The more I thought about it the more I realized that DS will still have to learn at the same pace as the other kids and while he might be stimulated for a while he will eventually get bored.
He got accepted into both programs and I chose Montessori. I talked to the principal before I signed him up and she assured me that he'll be able to work on his own level in reading and math since a lot of what they do is independent work.
Choosing a school for him has been one of the most stressful things I've done in a long time. Good luck and I hope that you find something that works.
