I would merely add that tipweight is the most important adjustment feature you can put on the airplane, and the adjustment most likely to be needed on a day-to-day or even hour-to-hour basis. Back in the good old days, using a rolled-up empty glue tube and hoping for the best doomed many airplanes to substandard performance, and airplane-to-airplane variation in the wood and other construction features made the "correct" amount of tipweight a random number - so you couldn't and can't *ever* get it right without being able to adjust it.
Even a 3-gram tipweight change on a 4-lb airplane makes a visible difference, and it can change as the air density changes, so I evaluate it on every flight and every maneuver- do I have too much, too little, or just right?
Brett