My pleasure.
And I identify with every single thing you just wrote, kimck! (Except that the uncomfortable relatives are my own parents, not my in-laws. At least not to my knowledge.)
If I may make a suggestion: expect the in-laws to hate the idea and to constantly criticize you. Make your peace with that and be able to accept their criticism with a peaceful, non-defensive smile and some variation on the following statement: "I hear what you're saying. I respect your opinion and I love you. But we are DS's parents and we have to do what we think is best for him. I hope you can respect us enough to accept that." You can't change your in-laws (or anyone else who hates the HSing idea); all you can do is change the way you respond to their criticism. FWIW...
As for being lumped in with people you're not like...I feel pretty fortunate that there's a large secular HSing community where we live, so the assumption is generally not that we're ultra-religious, ultra-right-wing, afraid of the world, or any of the other things that people assume without even thinking in other parts of the country. I've read enough blogs and posts on forums by other secular HSers to know that we're pretty doggone lucky to be where we are. It's a lot harder to HS in some other places than it is where I am. I just wish I had a better way to answer the inevitable (even if unspoken) question, "Why are you HSing?"
And I completely agree with you about feeling guilty/defensive about leaving the public schools. That more than anything is where I have felt attacked and judged--as you rightly note, Lori. I've actually been told (by someone who should know better!) that we owe it to the public schools to keep DS6 there. Um, no! Sorry! I find that notion to be patently ridiculous. I can't sacrifice my son to the good of the schools. My primary (and secondary and tertiary...) responsibility is to my child. The school will just have to get by without him.
But I still mourn the education I had envisioned for him. I know the one he's getting is a good one, but it's not the one I thought he'd get. I'm reminded of the great article that Grinity linked to that talked about planning a trip to Italy, only to be told at the last minute that you were going somewhere equally nice, but somewhere that was not Italy. It throws you for a loop. Ultimately you have to accept that you're just not going to Italy, but it can be hard to let go of the dream. I think that makes me feel defensive, too.
And finally, I think I feel defensive just by nature of having an HG+ child. In a culture that values conformity, that frowns on giftedness, that denies the possibility that a child is capable of doing "that," whatever "that" happens to be (reading early, doing algebra early, etc.)...I think I feel defensive about not being able to say "I'm HSing because my child is profoundly gifted and the school can't handle him" in a voice louder than a furtive whisper.
That's the part I think Dave has hit right on the nose. But frankly, it's the part I feel most defensive about.