With auto glass you get what you pay for. If you pay a cheap price you get cheap glass. I used to work in a PPG plant that actually produced glass for many uses, including windshields and side-lites and back-lites. I can tell you that there is "glass" and there is glass. Just because a windshield meets DOT standards does not mean that all windshields manufactured by any glass manufacturer are equally as good as those of another manufacturer. While a manufacturer's windshield may meet strength requirements it may have more distortion at the edges than another manufacturer's windshield, or it may have more bubbles or other defects. One of my jobs was working in an inspection booth on auto lite runs and we had a zero defect tolerance. I've since seen replacement glass coming from plants in China that would never have passed inspection at PPG for use in auto lites, too many bubbles. They aren't apparent when you look at the windshield under normal lighting conditions but drive into a setting sun and the defects become apparent. Look at objects through the edge of the windshield on cheap glass and everything will be distorted. That glass would never have made it through inspection at PPG.
PPG glass is now PGW glass. If you get PGW glass you are getting good aftermarket glass.
People look at glass and figure one piece is the same as the next. I can tell you it "ain't so".