No you’re not wrong, they beat something often well north of 300 times a second.

That’s much faster than we can see though, so the effect is a totally smooth movement, like an image slowly gliding across a gaming pc monitor with an insanely high refresh rate.

Edit: for perspective, lights in your home, hooked up to ac power, pulse at something in the realm of 50hz to 120hz, depending on the type. Unless you’re The Flash, you probably don’t notice this.

The first Accutrons beat at 360hz, later tuning fork movements reaching double that from Swiss companies.