I've had my 500 for about 20 years. It has never broken or malfunctioned. I got a combo gun, came with a bird barrel (fixed modified choke) and a smoothbore slug barrel with rifle sights. I have since bought a barrel that accepts choke tubes, and that is what I use for turkeys. The full choke does real well with #5 and #6 turkey loads. I've killed them no problem out to about 35 yards. Of course there are better tubes out there that will allow you to shoot out to 50 or more, but the fun of turkey hunting is calling them in close. I've shot deer, rabbit, woodcock, grouse, pheasant, and a few other things with the gun.
I like the older ones better than the newer ones. I don't like the new fore-stock shape or the lighter stock color. I'd guess the new ones still function the same though, and I've not heard anything bad about the reliability of the new guns.
They are a snap to strip and clean too. I don't know how that compares to the 870.
You can't go wrong by buying a 500, or a 535 for that matter. Just realize you're buying a Chevy, not a Cadillac.