Yes, it is all anecdotal. All I can tell you is that I shielded on of the inexpensive kits I built because it was noisy. That particular build lives at church. It was noisy there but worse at him because I practice in front of my computer near a computer tower, large monitor and under CFC bulbs. The guitar was noisy. I tore it back down to fix intonation issues, lined pick up and control cavities with aluminum flashing tape because it is what I had here and it became as silent as my other factory bass with active pups. That is anecdotal, BUT also based on my experience and results. I paint guitars, its what I do best. I'm wondering if I could add powdered metal to my first coat of paint, or a special coat, spray the cavities and create proper shielding.