It's impressive reflexes for sure. But sadly I think it also makes the fights a lot less interesting visually, they're just "spamming" (with incredibly precise timing of course) the same move over and over again, no swords clashing, no deflections, no dodges, no grabs, and of course there's the health sponge problem. Even an overhead hit with two hands as a Oni takes away like 3% of the enemy's health (and it's not even a real boss). Hell, even the ultimate Oni finisher near the end only chips away some health.
It's a shame they based Carnage difficulty around Issen mostly because I think it takes away from a lot of the game's strengths (the beautiful combat and the different ways to approach it).