Well, we went to Dick's last night. My girl walked right up to the counter and asked for both shotguns. She checked out the 870 for a couple of minutes, then asked for the Mariner. After holding the Mariner for about 5 seconds, she said "nope, gimme the other one back". She thought the Mossberg was flimsy (and I agreed). The 870 seemed like a much more quality firearm.
Before any Mossberg owners jump all over me, it wasn't really a fair fight. The 870 Dick's had was not your run-of-the-mill Express model (for $500 it better not be!). It came with some extra stuff, like a door breach/muzzle brake type thing and a really nice recoil pad, a nicer stock, and it also has a finish that was way nicer than any other Express I've seen (more on that in a minute). It is sharp looking, feels very well-built and very smooth. I haven't had a chance to learn too much about it, but someone on another forum said that this was a part of a special run of guns that Remington made for Dick's, but I don't know if that is really true or not. Either way, it is a very nice gun and well worth the $80 price difference in my opinion.
Now, as for the finish, I'll describe it and maybe someone can let me know what it is. It sort of looks like a carbon-fiber type finish. Looks sort of like black/gray fish scales. Any clue what it is called? Anything I should know as far as taking care of it?