I cannot comment on the Centaur group, because I have never ridden it!
OTOH, I have been riding on Chorus for about a year now, and am extremely satisfied. No problems at all, Campagnolo smooth, everything rides like a dream.
But I would think it over before choosing to pay more for Chorus. I am not sure I agree with what dennis dee says - do you really need Chorus? What kind of riding do you do?
Above and beyond ' bling ' factor [ok, the reason I purchased Chorus as opposed to Centaur!], I believe that the differences in performance on the road are not as noticeable as the nice marketing people in Vicenza might have you believe, much as my [few, I must admit
] shimano riding buddies tell me in moments of honesty when comparing dura ace and ultegra.
As for differences, apart from slightly more weight, I believe the other main thing is the bottom bracket axle length, which is 111mm on the Centaur (and all groups below it) and 102 mm for the Chorus and Record (for the doubles, triples are of course different). Then the Chorus 2004 has had the oodles of carbon fiber filter down from the 2003 Record, and looks absolutely mah-ve-lous!
In any event, enjoy the shopping and the riding!