The E-lenses had the exact same formula and glass as the professional lenses. 50 mm lenses were among the best Nikon ever made. That wasn't difficult because the 50 mm design was the standard lens for everyone. So, research and practical experience had eliminated all flaws years ago. And because of the large numbers sold, Nikon could produce them efficiently and cheaply.

But the E-series had much cheaper barrels and mechanics than the professional ones. So they are more vulnerable. Are you a war photographer?