I'm going the opposite direction right now from a semi back to a pump. My 11-87, which has been my go to gun for a lot of years, broke a little plastic piece that has something to do with the bolt/recoil spring or something that makes it eject. While I am waiting on the part to get here and the gun to be put back together, I started carrying a 870 backup gun. I had Sumtoy Custom Chokes cut down and rethread a barrel on it a couple of years ago. I put one of the Dead Ringer fiber optic sights on it.
I have been impressed with how good that sight looks in the field, and have used it to kill two birds with no issues. But, the thing I am loving is just how much lighter it is to carry that 870 than the scoped 11-87. On some of the long walks I've been on this spring, it has definately helped.
Out of all of the birds I've killed, I can think of only one time when I needed a second shot. And, after years of twice a year qualifications with a pump, I can cycle one of those quick enough to take care of any second shots needed. I suspect the 11-87 will go back to the safe as a backup until I miss killing a bird that I think the semi would have gotten for me.