Well, there are S and N prefix guns, and there are S and N prefix guns.
From the start of S prefix .44 Magnum production until sometime in the early N model 29 range the polishing and blue work were visibly superior to later guns. So there is a big difference from an S 130000 range .44 Magnum and an N 600000 range model 29-2 - but probably not a big difference between a model 29-2 in the S 330000 range and N1.