Lots of good points of view. But chosing a gun/gauge is more than just about efficient killing. If killing was the only goal, we wouldn't all be fascinated by doubles. A gas jack in 3" 12g is far better killing machine than some extractor, exposed hammer 2" damascus gun that has to be fed 4000 psi party poppers. Heck, some 12g autos can be as light as anyone would want.

A man should shoot what makes him feel good, not what someone else tells him to.