Yes, by all means... don't convert an AZW4 to PDF. It's already a PDF inside the MOBI/Palmdoc wrapper. It just needs to shed its skin. KindleUnpack (standalone or plugin) is your best bet for that (as was already mentioned).
With the KindleUnpack plugin installed, highlight a DRM-free AZW4, and select "Extract PDF" from the AZW4 submenu of the KindleUnpack menu (either on the toolbar or the context menu... depending on the options you chose when first installing the plugin).
Last edited by DiapDealer; 02-03-2013 at 02:43 PM.