From a functional and reliability standpoint, the 500 is comparable to a 590 and a 590A1.
There are a few fairly minor differences between them (barrel thickness, safety button material, trigger guard material, etc.) but from a personal use/HD standpoint, they are all relatively comparable. Get whichever one trips your trigger and shoot the begeezes out of it. You'll be fine with any of them. For a long time.
In my experience (I have both 18.5" 6-shot 500 and 20" 9-shot 590 models), I much prefer the 18.5" models as they are much more nimble and handle in-house much quicker and easier. The 20" models are better as hunkered-down, fixed-position models, as they are not so nimble, but have greater capacity. From a reliability/longevity standpoint, any of the 500, 590, 590A1, 870, 1200, 1300, etc. models will serve you with comparable reliability and longevity.
I swapped my 14.25" LOP synthetic furniture set for a 12.75" LOP Bantam wood stock set (which I refinished in oil finish) on my Persuader and it's the cat's meow now...
Here's the 590 set up similarly... but man, the 20" 590 is a beast and much less nimble around the house (especially with the 14.25" LOP factory synthetic furniture) than my 18.5" 500... I removed the heat shield on the 2-" 590 because it was un-needed/un-wanted weight and complexity