They must be comparing a wired track ball mouse to wireless mice.
Having used trackball mice quite a lot before optical mice became common place, I can see a good wired trackball mouse being more responsive than an optical or even wireless laser mouse, but you would have to buy a truly craptastic wired laser mouse to find a trackball mouse better. The only way I could see it even being a possibility is if your desktop is made of glossy plastic or something else that could confuse the laser.