"TRY a few and SEE"

Please don't misquote people, almut said:

"I'd say just try a few and see for yourself which one works best for the types of PDFs you'll typically be working with."

By shouting uppercasing "try" and "see" you seem to be attempting to bring different meaning to the advice given. I'm not sure if English is your native language, but your post reads as though you're being rude, also excessive use of the full stop character is pointless.

IMHO the replies you've received to this question are perfectly valid. People have pointed out the minefield of issues which may be encountered in this task. Given your rather glib question it is reasonable for people to assume you're not in possession of all of the facts (OCRing text, PDF file version compatibility, glyph-to-character reverse mapping and so on), we obviously have no idea what may or may not be in the PDF files you have yo deal with or what version they are, so the suggestion that you should try a few modules with a sample of your input data (a few PDFs chosen at random) would be wise.

Update: Fixed two typos.