Well -- that's a deep thought -- the real difference here is do you want a lighter weight, mainly upland gun, or do you want a 12 gauge do-it-all?
having both, I generally use the H&R because I carry more than I shoot. Anymore, the mossy comes out for one of two reasons:
-- I am hunting waterfowl
-- I am letting someone else use the H&R and the mossy is what is left.
However, if I could only have ONE GUN, it would be a Mossberg 500 or maybe an Ithaca 37, in 12 gauge. There are things that platform does that other guns can't.