I know there are plenty of people who can shoot doubles with a pump, but I'm not one of them. I find it impossible (you may find it merely difficult, or challenging) to acquire the second shot. For clay sports I much prefer a double-barreled gun. Also, if traps is your sport, you may find it easier to get proficient and consistent with a higher comb and rib (your target is always rising).
I myself have found by needing to pump the gun, you drop it down and get a full view of the rise or fall of the bird. This way, when I acquire the target with a fresh shell, I can visualize which direction it is traveling and how much lead is necessary. Also, being left handed, I grab the ejected shell in the air and drop in in my side bag before shooting the second target.