sunray:
You will never be fast enough to defend yourself with any firearm that is tucked away in a pack.
True, that's why you need to African Carry: (not my video)
Practice with snap caps, a LOT, (100+ snap cap shots) before even thinking about loading with live ammo. And something almost none of the training vids are clear on (at least none that I've seen - and this vid gets wrong) - your trigger hand does NOT touch the gun until AFTER you are shouldered and pointed at the target - you use the rotational momentum to get it up in place. You're pretty much slapping your hand around the receiver as you jack the slide, finger on the trigger at the moment of shooting. It takes a bit of practice to get right, but once you know it, you can do it with any long gun and be up and on target and pulling the trigger in the 2-3 second range very consistently. (The difference with bolt or semi autos is you use your trigger hand to work the action at the moment you buttplate hits your shoulder).
As for the safety Sally's out there - if you keep your off hand on the for-end where the sling connects, while you have it in carry it naturally points about 15 degrees ahead, and your body motion prevents it from ever pointing at your feet. Also, your bicep covers the trigger so you reduce the chances of a twig/branch catch on the trigger.
Carry magazine loaded and chamber empty anyway.
As for 870 v. DA Grizzly:
I have a 12.5" cylinder bore DA, tube mag and bead sight, and it's true, the finish will blow off in a stiff breeze. But otherwise, it's a tough, durable workhorse. I was actually out this afternoon blasting patterns, and with 7.5" bird or 00 buck, you're looking at 25yard (tops) effective range before the pattern is so spread out you don't have to worry about hitting what you're pointing at so much as the stuff around what you're shooting at. It is very much a "up close and smelling the bear farts" gun. Bird shot is not only useless vs. Bear, it will most likely just serve to piss it off.
Personal choice: Salt and pepper load. Load it so your first (panic) shot is 00 so you increase your hit probability, followed by slug, followed by 00, followed by slug, followed by "Oh crap, I just blew my wad, missed everything, and am about to become grizzly snack."
DA reliability/Quality:
Had zero problems with mine, and it runs smooth as butter. Mind you, when it arrived in the mail, the FIRST thing I did was strip it right down to nuts and bolts, gave it a thorough cleaning, which washed out a surprising amount of filings and grit, and that crappy preservative/lubricant/ectoplasmic goo that Norinco likes soak all their guns in. Then lubed it, shoved it in the safe, and clean it after any day I fire it.
And that's pretty much what you should do with any new gun, or turn in your license because you don't deserve to own a boomstick.
I like the DA because it's a beater, and it likes the abuse. I don't care about mis-treating it in the bush.