To be honest I think he's right. At least in terms of how day 9 plays the game, the way in which he beats his opponents tends to be the exact same. I think the opponents themselves are really fascinating (giant crab dude was great), and they have a number of varied attacks. But day 9 just has the same "block", "slash" rinse and repeat approach that makes it soo boring to watch.
I think the main reason (as usual) why I find his stream entertaining is 1) The visuals of DS3 can be pretty incredible at times 2) The monsters are cool, and some of the lore behind the items 3) I like the way other characters converse with you and what they have to say 4) Sean can be pretty funny sometimes.
But the combat itself is getting rather stale after a while. I think it is the kind of thing that is much more gripping when you are playing than when you are watching...but if I was playing I would honestly use a lot more variety. He uses only two moves, I *know* this game comes with more than 2 moves! :P