Laugh all you like Brad but I spent 20 years of my life as a tool maker (glorified machinist) and I can tell you that it has nothing to do with the purpose at hand. I've owned a Mossy 500. How many lifetimes will it have to last before it qualifies as good enough for home protection? We aren't talking combat here. Home protection. The odds are better that you'll kill yourself by slipping and breaking your neck than a 500 failing in a typical home defense situation. Its a decent shotgun. Not military grade but close. Nobody is saying that the 870 isn't a great shotgun - it is. It's just not that much better that it's a must have in a typical home.I can tell you this much if you would hand the 2 guns in this poll to a true machinist that could study each design and funtionablility of parts and what will last longer, the machinist would say 870 hands-down.
By the way the military buys Mossy 590s now. That would be my choice if I had to go into a bad situation with a pump. The 870 would be my second choice, and I wouldn't feel at all naked with a Mossy 500.