I am cautiously excited about this product and I’d love your thoughts on it. According to this news report, the glass can be retrofitted in doors that currently have 1/4″ glass. The FAQ page on the School Guard Glass website says that the glass kept the testing agent at bay for over 6 minutes, and has a cost of $1000-$1200 (installed) to replace the glass in one full glass door with the SGG4 product. The SGG5 glazing kept the testing agent out for over 12 minutes, at a cost difference of about $18/square foot more than the SGG4.
Considering the typical response time by police and the average duration of these incidents, glass that could withstand 6 minutes of abuse would be a big step in the right direction. The spec sheet on their website provides comparisons between various types of glazing.