where and when you will really see the difference is when the servo pots and gears get worn. As the gears wear the slop created in your old setup will actually be larger deflection of the control surface by 30-40% than the your new higher resolution setup.

On a gasser model they shake like hell and literally eat servos apart. The pots get worn and now the servo has a "deadspot" at the center location. This deadspot and any gear lash (wear) will be exagerated by a mechanical linkage that gives 30-40degs of travel. By reducing from 30+degs to 20degs deflection at max Travel adjust you have increased the resolution (how many degrees of surface travel per % of atv.) or another way is the degrees of surface travel vs the degrees of servo rotation. Basically you have improved your linkage by 30-40% resolution. You may not see it on new servos as much but put 50 flights on them and you will for sure.