I've bought a few used 870 riot guns and Wingmasters, and a few used Mossbergs 500, 590, 835, in my day, and used a bunch more. They seem equally rugged and reliable for my use shooting under 1000rds/yr (they short stroke equally well
) and the differences seem mostly negligible and superficial.
Perhaps Remington triggers are easier to work on, but I really don't think most people would care.
If I was looking for a good pump shotgun (and I always seem to be looking for a good used pump shotgun under $200!) I wouldn't hesitate to buy either one.