I was trying to make the same decision about 2 years ago. I wanted a versatile shotgun I could use for ducks and for HD. I was mainly looking for a beater to take hunting and not worry about. I purchased the Win 1300 b/c it was lighter and smoother than the Rem. The 1300 has been great for the field, its pump is smooth and fast it always brings home a brace of green heads if I do my part. It is easy to slog through the mud with this gun, nice and light. However as pleased as I am with it, it jams on 3" shells. I don't know if I am short stroking it or what. When it gets jammed I have to take it apart to clear it. A total pain the the butt. I have been able to replicate the jam with a relatives 1300 (it is the 7 shot HD 1300) Needless to say, I ruled out the 1300 for HD. That said it is a great field gun.
I recently purchased the 870 police for and I am very pleased with it. It is heavier and the pump is slower than my 1300 but it doesn't jam. I looked at the 870 Express HD as well, but the model I saw was pretty rough.
Anyway good luck on whatever you decide.