You have to remember there is a big difference in Remington 870's. A 870 Express is nowhere near the quality of a 870 Wingmaster or Police model. I would take a Mossberg 590 A-1 over a Remington 870 Express any day of the week, and twice on Sunday. When you compare these guns, you cannot paint with a broad brush.
What I think is a bit funny in reading through this, is how some complain one "rattles" more than the other. Complaining about rattle in a pump gun is like complaining about snow in Alaska.
With that being said the Mossberg 590A1 beat out the 870 in the Military trials...The point being...It's kind of hard to buy a "bad" pump shotgun...It's America's gun and they are ALL going to be going LONG after we are onto our reward.....
But then I think Ruger's "warning labels" to be the worst sin.
All things being equal, the military WILL go with the most cost effective, and some of those contracts are awarded on differences of pennies per unit. This is where the arguement falls apart, because military and civilian M500s are not equal. The real military kind have steel recievers, where only a few civy models have such. Now if Mossberg offered the steel reciever as standard, well then they would cost about as much as the easier to maintain 870, and what would the cheap skates use as their justification then?