I had one bike with Campy Chorus, but removed it and replaced with Shimano Ultegra/Dura Ace. The reason? Mechanics around don't seem to be able to work on it. My Chorus 10-speed group never shifted well after the first couple thousand miles. It ate up chains like they were Oreos, and I would end up replacing them at great expense because it didn't shift right unless you also replaced the cassette.

Putting Shimano parts on all of my bikes was the best equipment decision I ever made. Everything is compatible and the parts always work and last forever. My cassettes seem to last forever, and I easily get 5,000+ miles on chains. My bikes always shift perfect.

The one good thing I can say about my Chorus group is that it was easy to sell. After 10,000 miles of use, I sold it for well more than half what I paid, very simply. I can agree with about that regarding Campy parts -- they hold their value very well.