It is definitely true that larger burrs have more surface area to retain grounds. In general, I think most people consider the tradeoff worth it in terms of flavor, especially because in my experience the coffee that builds up in the burr of any grinder is likely to stay there whereas coffee that sits in nooks and crannies around the chute is likely to get cycled each time.
The knocker is actually hidden within the hopper itself, you twist and release it and it knocks into the burr. The basic idea for the design is that you have 3 rings, and each of them is a touch point, the bottom turns it on, the middle adjusts the size, and the top is the knocker.
Every burr grinder I've owned over the years (Cuisinart, De’Longhi, Braun, Black+Decker) had that awful static cling problem, although my newest, a KitchenAid KCG8433DG conical, is notably cleaner and quieter than all of the others were. For comparison, I'd like to see some real life on-the-counter evidence after a Velofuso grind.
BTW, there are a few different means of reducing static cling problems, including stirring the beans in the hopper with a moistened spoon before each run.
It is definitely true that larger burrs have more surface area to retain grounds. In general, I think most people consider the tradeoff worth it in terms of flavor, especially because in my experience the coffee that builds up in the burr of any grinder is likely to stay there whereas coffee that sits in nooks and crannies around the chute is likely to get cycled each time.
The knocker is actually hidden within the hopper itself, you twist and release it and it knocks into the burr. The basic idea for the design is that you have 3 rings, and each of them is a touch point, the bottom turns it on, the middle adjusts the size, and the top is the knocker.