There is absolutely no doubt, Adobe has far FAR more features. In a standoff between Adobe and PDF Expert, it comes down to what you want. The features aren't as rich as either PDF Expert or Adobe. My overall impression was that it was a little clunky. I can't speak to PDF Pen completely: I have used a trial version, but not the full version. This is an area on which I can speak with some degree of authority. For work, I often navigate huge PDF documents, often many thousands of pages a day.
