"If you're the one using it, and you obviously like one, then does it matter what we think?"
Yes, but the question is a reliabilty one, more than which one someone "likes" best. I'm just wondering if there's a difference reliabilty wise. Folks that have experience with either/both may have some useful input. I DO like the model 12 better, more for the takedown than anything I think, tho the history and character is interesting.
I think the model 12 has a good reputation for reliabilty, but am not really a shotgun person, so have little to go by. The 870 has a good reputation. I dont know how much of that is from being used so extensively, and others (like the model 12) may be as good, just not as well known, or as "renowned".
I've shot some informal skeet and sporting clays with the model 12, and have had no trouble so far.
I already have both, but the 870, not being a takedown, isn't as handy to have around so doesn't go very often unless bird hunting or shooting clays. If I had room for the 870 to go along in the truck on a regular basis, I'd have room for a rifle, which I find much more useful.
So, the basic question is, are the two closely comparable reliabilty wise?
BTW, my Model 12 probably has little collectible value, I found a well used and abused gun with little original finish, pitted reciever, and barrel already cut. I cut it to 20" put good rifle sights and sling on it, recoil pad, and had a takedown case made that gives me an overall length of 22" cased. The original thought was for a gun I could take through Canada while driving to Alaska, since handguns are not allowed for visitors, and be handy enough to carry in a day pack when out kicking around in the hills, and not wanting (or able)to carry a rifle. Maybe not as handy as having a gun in one piece, but infintely better than having a gun in the truck,...2 miles away when needed.
I've found it makes a nice travelling companion in the states, and fits in the overnight duffel bag when staying in motels.