Best PDF library

I will be generating PDFs. Which library is the most good?

I have examined so far:

http://www.lowagie.com/iText/
http://libharu.sourceforge.net/

What do you think?

PDF has an aditional benefit. It's excellet for office work, with its review and commentary system. The only thing I have seen that compares to that is Microsoft Word. And no, "diff" is NOT an excellent tool for reviews. But >>22 summed it up quite nicely.