Currently, when I send a client a link to download a file using the Dropbox share file functionality, they are directed to a preview page. When they click the Download button, they are presented with a dialog box prompting them to sign in or sign up for Dropbox. At the bottom of this dialog box, in text that more closely resembles a legal disclaimer, they are given the option to download without signing up.
As a paid user, I cannot entertain this dark UI feature. If I need to provide clients with an instruction manual on how to work around a dark UI feature, then it makes me look really cheap and really hacky.
Not only does it make me look bad, but it's also a really nasty look for the Dropbox brand.
Feel free to keep grubbing for frustrated free user signups, but know that it is coming at the expense of long-time paid users. You have 30 days.