CS vs MSP vs SuperSilver

I keep hearing folks who say their product is better... I read Metcalf's book.
Its great. He goes for 5ppm as the optimum amount. Mild Silver Protein is 400
ppm and now supersilver.net say they have the latest and greatest. Metcalf says
that anything past 20ppm will not get absorbed by our bodies. So, anyone save me
research time here? Other sites to read?
I know everything can affect the solution. Can't see much with my test gizmos, so
I go with the laser pointer trick to test the thickness of my solution and faith.
Don't want to spend superbucks here for more test equipment, I'm already up to
$20K in gizmos to test things... Opinions, thoughts, welcome. Thx, PT