A resposta curta é que o PDF será impresso mais rapidamente.
De acordo com a Adobe:
So why is PDF more advanced than PostScript? A PDF file is actually a PostScript file which has already been interpreted by a RIP and made into clearly defined objects. These objects are viewable on screen not in code, but in visual objects that everyone can see. Because these files are already interpreted by the RIP, they can be more reliable than an EPS or a .PS file when printed. Additionally, because EPS files and .PS files can be easily converted to PDF and viewed on screen, print service providers can benefit from seeing the file after interpretation but before they send it to their printing devices. This may allow them to see errors in a file before wasting paper, film, or plates. This can be a terrific timesaver for people who run service bureaus or operate printers, and the result is that files print faster, more accurately, and with fewer errors.