Wow, that's a tough one. Could you do a "trial" with the regular classroom so that your DS could get back in the HG classroom if it doesn't challenge him enough? Would after-school/weekend social activities satisfy your DS? My DS's 2nd grade class is so structured, they barely have any time for free socialization except for the 30 minute (rushed) recess. I feel he gets most of his socialization through playdates and other activities.