I have several 870's. All mine are field guns. I don't like the idea of using a pump shotgun for HD, but then again my home doesn't often need defending.
A shotgun is probably the most efficient stopper there is and if I was in a close quarters gunfight, I would rather have it than anything else. BUT, a HD weapon (at least at my house) is going to spend 99.99% of it's time NOT being used for HD - and I don't want to have a pump shotgun sitting there with one in the tube all the time. If I were to need it, I would want one in the tube. I've seen several accidental discharges in my life, and almost all of them have been with a pump gun - somebody being stupid or careless. Don't rely on the safety.
So I use my shotguns for hunting and take my chances at home with a DA auto or a SA or DA revolver.
We do a good bit of informal skeet shooting every year, and I've seen guys with cheap, beat up 870's outshoot nicer guns many times - and vice versa - it's all about what fits you and what you are comfortable with.
Personally, if I lived in a place where I felt it was necessary to keep a loaded 12 gauge by my bed, I would probably move. So just keep in mind that you will (I hope) be using it for recreation far more than you will be using it to shoot intruders, and buy one that fits you for that first.