We do not give the PDF version of the TAG enough love. There are a big pile of issues with it, all while the HTML version is very usable and in very good shape. As we are not doing a very good job at maintaining the PDF, we should at least consider dropping it entirely in preference for the HTML version.
Worth noting is that the PDF version is useful when you want to search the whole documentation as the HTML search functionality is flaky (bug 7973). We should probably fix the HTML search functionality before considering dropping the PDF TAG.