Integrated quality control
While typically as many PDF files as possible are accepted and printed, often you still need minimal quality control on incoming files. In a web-to-print portal for example, you might need to at least warn the customer that fonts are not embedded, or image quality is going to be insufficient. And you might need to check the PDF files uploaded by the customer to the order placed. Does the final trim size and the number of pages in the PDF correspond to the product ordered by the customer for example?
pdfToolbox contains a class preflight engine that can answer many of these basic questions very quickly, and in scenarios where time is really critical a QuickCheck engine can prove to be even faster, even on very large PDF files.