I have a Benelli semi auto that my wife bought me for my birthday a while back. it isn't the M1 but I think the action is the same. It's a beautiful gun, reliable and a pleasure to shoot. You can actually feel the action working when you fire it. Less recoil than I would have expected for such a light gun.
I have a friend who has an M1. It isn't beautiful, but it's reliable and also great to shoot.
I don't know about the Browning pump you are comparing it with. Never touched one. If your finances can stand it, I suggest that you buy the M1.