Both have been around forever and that's not by luck either. Both are good shotguns and serve as very good buys for the price range they sit in. See which one of the 2 feels better when you pull it up, you might like the pump release more on the Mossberg which is behind the trigger guard more than the Remington's which is in front.
I just personally bought a 535 Waterfowl / Turkey combo in Mossy Oak break up. I like the release on the Mossberg more and I was looking for a gun to take all the elements so the Moss fit the bill for the right price. If I knew it wasn't going to get beat up and go through hell getting I probably would have spent a little more to get a Benelli.