One thing that is very important to look for in buying a shotgun is "fit." You should actually settle for a shotgun that fits rather than a particular model.
You don't "aim" a shotgun, you "point" it.
When you throw the shotgun to you shoulder it should stop so you are looking straight down the barrel with a proper cheek weld. If you have to "adjust", like you would your rifle, your cheek weld then you won't hit what your pointing at. If you see too much of the receiver top and barrel top you will shoot high. If you don't see the bead well you will hit low. And that is where you will point the shotgun when you are in a hurry, whether shooting birds or goblins.
If you don't think the 870 fits right try the others, including the 870's with synthetic stocks. Once you try a few you'll see what "fits" and what doesn't.
I have found that only wood stocked 870's and 1100/1187's fit me. Not even the synthetic stocked guns of the same model. I worked for a few years in a gun store and tried every shotgun that came in. Nothing fit like the w/s Remingtons.