08-10-15: PsagIf one has a high resolution system, any change is easily audible. I can easily pick fuse orientation in a blind test.
Looks like a worthwhile article. But it can't really be used to judge the value of ground boxes. To do would be analogous to judging an amplifier based solely on its specs.
After spending big $$ on a tweak, it can cloud your judgement. Whether it's different or an improvement is up to the owner to decide.