One comment about Montessori, just to provide a counterpoint: some of us had less than stellar experiences at Montessori pre-Ks.
Montessori is a lovely theory, and when it is practiced appropriately, it can work wonderfully. But sometimes the practice can be a little too lockstep for HG+ kids. If a child must do activity A before he can proceed to activity B, it can shut him down. (It did my son.) Some GT kids need to start in the middle. If that's not okay with the teacher or the school, it's not good for the child.
My advice is to look CAREFULLY at the individual school and teachers. In my experience--and that of many other here according to previous conversations about this topic--the specifics of the school and teacher and how open they are to individual differences matter significantly more than what general philosophy the school embraces.
And be aware that the director of any school (Montessori or no!) can tell you whatever she wants about how individualized the school will be for your child. If the *teacher* doesn't "get" your child or isn't on board with providing different work--even at the pre-K level--all the promises in the world are meaningless. Flexibility and responsiveness to your child's needs and a willingness to take every child starting from where they are are most important in a pre-K.
IM(not so)HO...
