Re: Reading PDF from Dropbox
In Evernote app on Android, on your note screen, you may press the "Share" button, then find and press @Voice icon to send you note to @Voice app, or to add it to the reading list. This is a lot faster than saving a PDF to Dropbox and opening the PDF from there in @Voice app. Or you may copy the "sharable link" in Evernote and paste it into @Voice app.
When you save something to Dropbox, it may take the local Dropbox app on your phone some time (often long time) to sync the local data with the Dropbox folder on the server, that's why you have these delays. It is not something that I can control from @Voice app.