I never said anything bad about the mossberg's performance, and I really can't because I've only shot them a few times. But I don't consider a rattling forearm a petty problem. IMO, they just look and feel cheap, but then again, they're a cheaply priced gun. That is just personal preference, but then again, I'd rather be shooting a browning A5, personal preference
Both the 870 and 500 are on the cheap side of things, goes with the territory. They are also both very good guns.
IMO they both kinda look cheap, Remington's Express with the flat finish and weird striped wood. Kinda off topic but it really gripes me they gave the Marlin 336W the same exact treatment. The newer 500's with the really bland featureless wood are pretty boring.
My 500 is old enough to have very pretty walnut, kinda boring engraving on the receiver and a gold trigger. I got it used in 1996.
I was playing with a new Winchester the other day at Scheels, price wasn't bad, made in Turkey of course, and synthetic stock/forearm. Action felt nice and it felt nice at the shoulder... I highly doubt I would ever be able to dig up a slug barrel for it though.
Not really sure I would fuss too much for a different shotgun. What I have works well, I would rather put the money towards something a little funner... like a nice levergun or a pistol.