It has been awhile since I shot a whip, but if memory serves me, they were both very comparable in weight, both felt you were shooting a feather. I am guessing the whip has a touch larger sight window. The Whip is not as heavily R/D, and not as quick, but both are quiet as church mouse. I would say the centaur is a touch smoother.
As far as grips go, they were both very comfortable, and the centaur tends to be a little higher wrist, but both are pretty much locator grips IMO.
Can't go wrong with either one!
Oh and I think only one comes with carbon as an option.