Rated 5 out of 5 stars
I have used PDF Download on many computers over a period of years and I never had any issues whatsoever. PDF Download simply gives the ability to choose what to do with a PDF file as opposed to having your browser decide that for you. If you choose to download, it also produces a small graphical blue bar at the browser's bottom add-on bar which slowly "fills up" until it is finally "full", indicating that the download is complete. It helps you to have a quick visual image of the latest PDF files you downloaded. A quick double click opens the file, though right-clicking gives you the usual options, such as opening the downloaded file's containing folder. Since I've never had any issues with this, I give it 5 stars. However, if it causes any issues with your browser (I see some people have had some issues) then by all means uninstall it. I should add here that while this is a useful app it is by no means essential.