I'm a big fan of PDF files in general, but for purposes of my work with RM they have a problem. Namely, I use GedSite to make Web pages from my RM database. GedSite does a good job of supporting media files that I have linked into RM because it will place the media files into the Web pages that it is making. GedSite takes the PDF files that I have linked into RM and places them in the Web pages it is creating just like it places JPG and PNG files into the Web pages it is creating. But Web browsers don't support PDF files. A user can download a PDF file from the Web and then can view it, but that's not the same thing as viewing it directly in the browser.
My problem then becomes creating JPG or PNG files in situations where it's much easier or more convenient to create PDF files. This is especially a problem with multiple pages such as you might encounter in a scrolling browser window. My #1 go to trick is that I use Snagit for screen captures. It has a couple of different options for capturing scrolling windows as you might encounter with a browser. If all else fails, I do make a multi-page PDF file with the browser and use the free version of PDF XChange Viewer to convert it to JPG or PNG. The only disadvantage is that the free version of PDF XChange Viewer creates multiple image files from a multi-page PDF. But that's the best solution I presently have.
The overarching issue with PDF files is that as wonderful as they are, they are really text files and not image files. Lots of users don't believe this, but it is true. They are rich text files that can contain embedded images but that's not the same thing as an image file. It's no different than embedding images in a Microsoft Word file, in an Excel spreadsheet, or in a PowerPoint file. And it's further confusing because it's very common for a PDF file to contain a single embedded image and no text. But it's still a text file and not an image file.