I actually had the opposite - a sense of vertigo while I was watching, like "Why aren't I feeling directional changes and acceleration?"
You could probably figure out how quickly the tip of the sword is spinning if you figured out the speed of revolution and the length of the sword and the arm. Given that when you hold a sword out at full extension and spin, it has to complete a wider circle than your shoulder in the same amount of time, the sword tip will be covering more ground in the same amount of time. So technically, even though it has the same speed as your shoulder, it is moving faster. Or, moving differently. I'm not sure. That's about the extent of my physics.