Yeah, that's the only advantage that I see.
I shoot left and grew up on a 870WM. Never bothered me, learned to keep my trigger finger curled around the trigger guard to the safety. Doesn't take much longer to press and then put it on the trigger than pushing with your thumb then moving your trigger finger.
I had a Browning BPS Upland Special 12 ga in the 90's...I shoulda kept that one too. That 20 ga would have been real sweet.
I bought a 500 used about 45 years ago. It was kind of worn and beat up, but it was cheap. People would shake it and laugh at the rattle. They said it was broken. That old rattly 500 has been on hundreds of bird & rabbit hunts, been loaned out dozens of times. It has fallen from a boat into swamp water at least a couple times. It was my beginning trap gun. It was also the beginning trap gun for maybe 10 friends who were just learning the game. It still sounds like it is broken when you shake it, but it has never failed to fire. If I was invited to a hunt tomorrow, I would not hesitate to take it. I hear the original 870's were about the same. The higher grade 870s from the 70's were pretty nice. I really liked the 870 TC trap models. They are pretty few and fair between, or pricey.
The Remington M31 was discontinued for the same reason the Winchester M12 was, money. The M31 probably would have rivaled the M12 in sales if it hadn't been for the depression and the M31 was a bit more expensive. As far as quality and overall finish, I think both the Remington M31 and Winchester M12 were/are superior to the 870.
That is pretty much the order for me too, 120/1200/1300 way ahead of a 500 and a 500 way ahead of an 870. The older models belong in a separate discussion, as most were on a different level of manufacturing. People always frame the question as 500 vs. 870 but both were far behind the Winchesters in quality, the 1200 and 1300 especially but even the budget 120. The Winchesters didn't rattle, were smoother, and didn't have the safety in a stupid location.
