RE: 870 super mag vs mossburg 935
not trying to change your mind, but have you considered the Browning Gold? Comes in Mossyoak breakup with the duracoat finish 3" mag capable auto loader for ~$725. If you can get to a store that carries Gold's just pick one up and cycle the action, it is smooooooth. Just trying to give you another option, as far as your question, Id pick which ever one fits your shoulder the best......(although I am kinda leaning towards autoloaders here lately, since you are going to get a pad on it you can have your smith adjust the LOP)