@nandric (Slightly off topic)
One should use the weight which can be moved nearest to the pivot. The least inertia is the result.
Is this actually true? As long as what you're balancing doesn't change (i.e., the cartridge & headshell stay the same), doesn't the force on the counterweight side also have to stay the same? So if you use a heavier weight and get it closer, the end result is the same as using a lighter weight further out. In other words, inertia is the product of distance & mass, but you're changing both in order to balance the same thing on the other side.