Regards Image2Pdf, it did a good job, but when used to transform META to get real (not image) pdf, i had _many_ issues related to font translation. Usually the problems came from the fact that font names are different in Spanish than English, so the library wasn't able to make the right font translation. By that time I worked with the author of the library, but we weren't able to find a solution for the issue.
I also used PdfCreator, who gave me one of the best results in terms of quality. It really produces very small pdfs, and you are able to select and copy text from them. The only issue I had was that managing the printJob queue is time/resource consuming, and eventually having more than one program producing pdf documents can be really difficult to manage. To produce masive pdfs like in payroll printing, it didn't make.
When pdf size and quality matters, there is nothing like use a library that write real pdf documents, like Haru. Realy fast, lightweight, and the best results you can get. You may take a look at the following library, Mastintin and I were working on it some months ago. It will give you a good starting point to help in the convestion of current FW printing code.
https://bitbucket.org/carlos_mora/pdfprinter/