I commute on a road bike (with a racing frame). I wouldn't really commute on anything but a road bike. I tried commuting on a hybrid for awhile, and the upright posture made me feel like a human sail. One of the advantages of the nice smooth roads here is speed, and the hybrid didn't allow me to move all that fast. I'm converting a bike with more of a touring frame geometry (and fittings) as my all weather bike. It's a road bike too.

Since on-road racing is carried on with road bikes I can't see responsiveness as a problem, although stability under load can vary considerably. Even the racing bike handles the sort of things I carry to work well, though (a change of clothing, my lunch and snack, whatever work-related manuals I've carried home, and the tools and accessories related to the bike itself)