COC controls here and OP certainly got what he contracted for. In light of what's ocurred, an 8-hour delay on a significant intl. trip is pretty good. UA may choose to send some goodwill credit of some kind, but it won't be much. Doesn't hurt to write a short note listing the pax names, PNR's and ticket #'s and listing the original and offered itinerary. If the kids are little, give their ages.