I agree that the teacher sounds like an unusually good one, but I think that's irrelevant to the question of whether you should place your kid there. The key question is, would your kid (and your family in general, including you, you matter too) be better off with him in this classroom than with homeschooling? You shouldn't feel like you should take the spot just because the teacher is so much better than you could have asked for, if it's still not going to meet your kid's needs.