I am late to the thread, but I thought I'd mention one thing I didn't see already mentioned. I've had children at several schools and don't currently have children in our local public school; I've also watched families leave schools. I think it is very helpful to people to know you are leaving for a better fit, yes, but also that you are not leaving because you are dissatisfied with the school in general. People want to feel like they've made a good choice, it's unsettling to watch families that you respect pull their child out of what you think is a good choice school. I have been careful to talk about how great the schools that we've left have been in x,y, and z, and how we will miss p,d and q... You will get a better response if you let them know there is no "hidden" deficiency in the school you are leaving (if that makes sense)
