Serious Eats
Pre-Packaged Spring Water Ice Cubes
Print magazine's "Consumption Issue" takes a look at Ice Rocks, prepackaged spring-water ice cubes. They are:
... hermetically sealed, perforated cube trays of spring water. Don't let the name fool you—these cubes still require freezing, only the first hint of egregious over-consumption inherent in this product. Besides the plastic trays, the package includes peelable lids and a secondary structure with high-gloss UV coating for a wet look. Worst is the slogan: "The New Ice Age." ...
Even if you made the argument that you didn't want plain ol' tap-water-based ice mixing with your precious bottled water or with your cocktails, wouldn't you be better off freezing the bottled water of your choice in your own ice trays?