If you want to immerse yourself in great controversy, google "hot stamper" or the company selling these records--Better Records The claim is that, even within a particular issue of an album, there are certain stampers that are better than others and the resulting pressings are the ones to covet. Some hot stampers go for thousands of dollars.
I have not bought any of these hot stampers myself. However, long before hot stampers became a thing, a friend played two very clean versions of a particular record--both original pressings, both with same covers, dead-wax markings, etc., yet one sounded much more alive and vibrant. Were the two records from different pressing plants? Was this an example of a "hot stamper" vs. an ordinary stamper? I don't know, but, sort of thing adds more complications when hunting down versions of favorite albums.