According to the instructions for the CD Sound Improver the edge of the CD is reduced to 0.2mm thick by the beveling process (from a nominal 1.2mm thick). At this thickness the polycarbonate edge will be fragile and damage prone. Easily chipped.

Putting aside the question of whether or not CD beveling has any real merit, the manufacturer makes no mention of this.

CD rot occurred in early compact discs precisely because the aluminum layer was too close to the edge of the disc, meaning damage to the edge of the disc resulted in oxidation of aluminum layer rendering the disc unplayable. It seems a little unwise therefore to go shaving the edge back to 0.2mm. Time will tell, but I'd suggest wholesale beveling of a CD collection might not be a smart move.

CD's are not nearly as tough or everlasting as was first suggested.