Saw the email about the promo price, so decided to try this. To date, I primarily use Acrobat or NitroPDF, running in a Windows VM under Parallels. I keep hoping for a Mac PDF program that works as well as the utilities on the Windows side. Anyway I tried loading several PDFs that work fine in Acrobat Pro (windows) and NitroPDF. Several failed to load, or caused PDFPen to crash during editing (mainly tried substituting text and annotations). Some that saved fine in PDFPen and appeared to be okay, I then tried to reopen back in Acrobat and NitroPDF. On Acrobat, there was one file that caused an opening error saying the PDF was corrupted. On NitroPDF the same file loaded, but some of my edits didn't show, AND the file was missing a digital signature that was previously in the file that I had not even touched in PDFPen.
These files were, IMO, not particular complex and definitely not large (largest was maybe 20 pages). Can't afford my windows clients to have ANY issues with PDFs I exchange, and majority of them use Acrobat (either Reader or Full version) or Nitro, so based on my experience I can not recommend this software in its current state, definitely not for Business purposes if you must have absolutely no issues (legal docs, signed contracts, etc).
(FYI, I use Acrobat Windows just because I already have a license, not because I have any concerns about the Mac version, and most of my clients are Windows, so its the best way to ensure compatibility if I know I can open a file using Windows utilities.)