It's hard to say whether the 500 is the best of the cheap guns or the cheapest top quality guns, so....
Mossies rattle, the safety's in the wrong place if you want to add a Choate style stock with PG, and they're not the best choice if you shoot a case of shells a week.
I doubt they'll last as long as an 870, but IMO they'll last long enough. Like 2-3 generations...