My reasons:
The longer barrel will slightly delay the unlocking, it needed that with the full toot loads.
In a hunting pistol, every bit of power your can get is good.
I can now shoot pretty much any lead bullet I want, probably never will, but I can if I want.
I actually think the extended barrel will look cool, I know thats of no real use for anything that matters... KKM will make a barrel to any length you want (no extra charge), I considered 7.5" because that is a popular length for revolvers but I think the 1" extension is enough without protruding too far out of the holster.