There are a lot of blades that are crazy fast and too fast for most players. Sardius, Primorac Cabon, Schlager Carbon, Garaydia T5000, T11. They are all in the same basic speed class.
When you watch a player like Schlager who actually used a blade that fast, and you see his game, if you understand the sport you will probably understand why and how that worked for him. But there are so many players who are intermediate level or lower who use crazy fast blades like that and have no idea why it is preventing them from improving as fast as they could.
It is fun to bang a ball around with a blade like that. If you have pretty well developed technique you would be able to use it how it is meant to be used. But most players at that level would also feel why they don't want to use a blade that fast. And the ones it would work for would be able to tell it worked for their game. But a player below an elite amateur or semi-pro level would have no idea what that blade is preventing them from doing.
Note that most top pros don't even use a blade as fast as that.
With a blade that is slightly slower, you can get much more arc on your ball and therefore you can choose if you want your ball to land deep or shallow. The balls that land closer to the net allow you to create wider angles. The arc on the ball, when there is sidespin translates to hook. If you take a shot wide with a lot of hook on it, it is much harder for an opponent to handle. You see pros do that over and over when they go wide they add more sidespin so the ball hooks.
A faster blade like T11 ensures that a mid level intermediate player will NEVER develop those skills.
A T11 or a Sardius will cut down your arc and make your shots land deeper which necessarily forces you to cut down the angles you can make with your shots and make you a more predictable player. Now, a top pro may know how to benefit from that. But an intermediate level player will just have so many tools taken away from him before he has even developed them.
It is worth having extra information.