Some years back I inherited a full-grown male GSP with no training other than house training and obedience training. He would find and point on fur and feathers. He would hunt down and kill varmints around the place without prompting. He nabbed several common birds on the wing that were flying too low for their own good. He was happiest when, after a point, the rabbit would break loose and run and he got to tear after them like a bolt of lightning. He was a wonderment to observe.
I have no doubt that were I in the market for a gun dog, I would go GSP.