I know exactly what you are going through, and am sure we are not alone!
It isn't the intelligence or necessarily the subject matter that is the issue it is the attitude where the issues begin. I love hs'ing my son, but his attitude / impatience / rudeness / and inability to accept mistakes makes me insane! Therefore we had to put him into a GT program in town. We are not happy with the program, he complains constantly about how easy the work is. As we see it he is backsliding, and gets away with doing just the minimal amount. It is really depressing for us, but I want to be his MOM and not someone with whom he takes out his frustrations on. He always appologizes afterwards, and he's commented that he doesn't know why he gets so upset with me, yet with his teachers in school he doesn't get angry with them! (I'm glad he sees this - but wish he could control himself - and not go for the Power Struggle)
We are presently looking into relaxation techniques for him to learn, and have consulted a behaviorologist who teaches 'how to relax', and 'how to know when the feelings are about to erupt' and 'how to avoid those situations'. We're hoping that teaching him to control his outbursts, and understand rather than trying to control all situations and thereby inducing a Power Struggle, will in the end allow us to hs again.
Not sure if I've gone off topic - sorry if I did. But I know many families that have these intense issues. I too appreciate all the posts with such great advice!
