I prefer an auto...most prefer pumps.
Good pumps are about a third of the cost of a good auto...which is part of the reason so many prefer pumps. Plus, a pump allows the operator to have more control of the firearm...for example, it is easier to chamber a round from the tube in an 870 than it is in a Benelli auto.
I terms of actually firing the shotgun in a defense mode, a pump forces the operator to be in 'deliberate control'...which is definitely a good thing.
Just my opinion...I'm sure you'll get a lot more.