From Uwe Möser in the user mailing list:
I made a small project which creates 32 pdfs with PDFBox and iText. The output is:
Time elapsed PDFBox: 2521 msec. (2305msec loading)
Time elapsed iText: 661 msec.
It is possible to improve the load function?
It is possible to create a template document before the loop?
Tested with PDFBox 2.0.6 and iText 2.1.7.