On DCUM there seems to be a sort of bandwagon effect about private school that seems to boil down to parents worrying, "if others think private is better, then we must be missing something and doing our kids a disservice by sending them public." There are various manifestations of this, from "testing will torture my kid" to "private school instruction is uniformly better than public school instruction" to "my kids will get 'polish' in private school" to "my kids will have better college options from private school" to "kids can't learn in classes with over 20 kids."
Obviously some or all of these things may be true for some families--families who live in bad school districts or with kids who really need the small classes and individualized attention. For these children and family, private school may be unambiguously better.
None of this is true for all kids, all the time, however. Some of it is demonstrably wrong for many kids. Yet you will often these ideas presented on DCUM as the gospel truth. It's hard to avoid the constant drumbeat of "private is better." Like the rest of us, you say you have wondered about this yourself.
But you're asking the right questions, about what's best for your kids as unique individuals.
Like 20:59, we also started in private, are now in public, and are very happy. If it helps, despite the high pitch of angst in the private school forums right now, we families who have chosen public school are still in the vast majority.
