Orracle's are nice, but overpriced. I am a diehard Cocker fan, but they are something to get used to. Any monkey can shoot an Impy, and They can kick out balls like no one's business...
Shoot 'em both if possible. Like Mr. 'Side says, they are completely different in feel. If it isn't possible, think about the sort of player you aspire to be... layin' down a rain of paint scarin' the timid into their bunkers (imp) or the shoot to kill deadeye one ball one fool takin' a walk type (cocker).
Also, isn't there a pretty significant jump in price from the Impulse to the Orracle?