[JohnnyP]

Pyrex has been cheapened:

http://blogs.discovermagazine.com/80beats/2012/09/13/pyrex-glass-isnt-as-shatterproof-as-it-once-was-report-finds/#.VxdZPij3Rj4

[SunkenCiv]

Corning sold the Pyrex trademark to some knockoff joint in China, and the new vendor’s glass is just glass. Original Pyrex is of course still available used, either online, or (much cheaper) at thrift stores, garage sales, estate sales, and the like.