The 20ga 870 Express that has been getting it done in our family for a dozen years or so is awfully confused about all the slagging in this thread. lol It's even more confused because the metal still looks almost new, only finish wear on the laminate stock. (Remington's laminate stocks only passed by the top-coating room, never went in lol) Even has a shiny, non-problematic/non-modified chamber.
Would be easy to read this thread and believe that 870s of all kinds aren't out chugging away reliably every single day, even guns made since the legendary Wingmasters. And you'd be wrong, cuz they just are.
I would take a new/used 870 express over a new Mossberg 500 today, but mostly because they shoulder better for me. I think they're both really good guns and yes, Wingmasters are/were better made, better finished guns than the Express were but I also don't put guns away wet or dirty. I've worked on enough Expresses to know where people are coming from, but I also think it's a huge exaggeration to suggest that any 870 that isn't a Wingmaster isn't as good as a 500/590.
My favourite gun to use hunting grouse is an old Lakefield Mossberg 500 in 410, some people slag the aluminum receivers (vs steel on the 870s) but that debate has been settled 100 X over. I like the reduced weight on an already light shotgun.
I only have one shotgun on the wish list and it's a 20ga 870 Wingmaster LW.