does the campagnolo chorus is as good as ultegra? or does the record? I was thinking about changing from shimano to campy. and my other question, does a campy rear derailleur works with a shimano cassete?

chorus is easily as "good" as ultegra, i would argue its better, but thats a can of worms. record is essentially the top of the line. i was surprised to see the pro's ride record as opposed to super record, so take that for what its worth. you cant beat the durability and functionality of campy stuff, especially chorus, its a fantastic group.

and no, dont mix campy and shimano stuff, if your going to switch over, make the commitment or stick to shimano/sram

and about the centaur?

centaur is a great group as well. very functional, good durability.

in case you didnt know, currently campagnolo is moving to 11-speed groups. athena, chorus, record and super record are all 11-speed right now. centaur and veloce are 10-speed.

a great value right now is the athena group. i've heard some very good things about it, and it gets you into 11-speed.