I see most of our people now, especially the younger ones, jumping out on calls with AR's, since just about everyone has one now.
We were all issued new 14" 870's in 2010. Those of us on SWAT got rifle sights, the rest had bead sights, since, you know, only SWAT needs rifle sights.
We still use them on SWAT some, and I will carry mine sometimes when clearing a house. I don't see many people grabbing them outside of SWAT.
We did have a fatal OIS where the officer used an 870 years ago (00 buck). It was very effective.