Everything Pat said. Plus, carbon fiber is light and strong. It allows bicycle frames to be shaped in unusual ways. Ithink that one piece carbon frames can be especially beautiful. Carbon fiber frames can be "tuned" to specific ride characteristics: compliant in one plane, stiff in another. Some people complain that carbon feels "dead" to ride.
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Religion is a good thing for good people and a bad thing for bad people. --H. Richard Niebuhr