I've been commuting on a full carbon LOOK KG461 or a steel LeMond Zurich (mostly on the LOOK though) for about 2 years now. My commute is 10 miles one way and it is not flat at all. I live in SoCal though where we have wide bike lanes, relatively smooth roads, and almost no rainfall to speak of. I carry the bare minimum in a back pack or a small shoulder sling and leave things like towel, shoes, belt, toiletries and a couple pair of slacks at work.

I love commuting on my road bikes and wouldn't trade them for anything else. They are responsive, fast, and I always enjoy my commutes on them.