I’ve bought and used all the premium glasses over the years. For a long time I stayed away from PDI due to the cost, but after buying a sheet for Safe Cracker because it was the only company making glass that size I was blown away.
Pretty much everything about the PDI glass from how it’s packaged to how it performs is better than the other options out there. Stern’s HD glass is nice, but it’s not PDI. Invisiglass is my least favorite of the three.