I believe he needs more exposure to older children, but at the same time I can't imagine the kid doing the same lessons for three years!
What type of exposure to older children will he actually be getting at the public preK? Have you visited and observed? Wouldn't he be in with other same-age kids?
I would leave him at the home daycare since you are happy with it.academics not even considered, the the I think my kids benefited from the most before entering kindergarten were consistent (ie not changing), loving, caring caregivers. Being in a situation where your child also has stimulating and appropriately levels academics is a wonderful bonus - I won't want to give that up. My kids also still see some of the same kids they went to preschool with in various after school activities... Not because we plan it, they just happen, and because they spent a few years together including that last year of preschool, they remember each other and enjoy seeing each other. It sounds like he small setting your ds is in gives him the chance to form that type of friendship.
Best Wishes,
polarbear
