I grew tired of Centaur after 6 months and a few hundred plays... I had a very nice one. I would only sell a Fathom if I had two of them.
Actually, I even prefer EBD over Centaur but don't misunderstand... I think Centaur is a better game, I just couldn't love it like EBD.
Hard to say on trade but if you have a decent Centaur these days, you could probably trade it for just about any Bally that you would want.