I'll shed light as an inverted player:
It has no benefit to turning into your swings, as there is a delay as you pull your sword back, so that is entirely false. Maybe if it works in your head for, say a right swing for example, to move left -> right -> stop -> follow through right. Otherwise, if you're moving right that entire time, you're going to spin in a circle. If anything, default controls is a rocking motion, and would be right to left -> right.
I simply inverted because when I learned the game, I thought of it in the same way Butan mentioned, like a wii-mote. I want my sword to go from left to right, so i move the mouse left to right. That's just it - some people swear by inverted controls, but honestly its just how your brain functions. When I played console shooters years back, I went from regular, to inverted, to regular, to inverted, back and forth maybe 5 times.
So be reassured, you're not missing out on anything. You might confuse a few people who instinctively read character animations the default way, though as kafein just mentioned ^, it seems otherwise, and completely natural to block it. Nothing game-mechanic wise though.