I have been using Diigo for a long time. This has been very useful. I don't have to re read the document again when I come back to it.

Only Complaint:
Please add a menu option to open the otherwise impossible (using mouse) "Annotation Toolbar"
For a long time my workaround was to do a dummy highlight, that would trigger the toolbar to show up and then I would delete the dummy highlight.

Now I know there is a keyboard shortcut for it "ctrl+alt+a" but for a new user or even an old user who has forgotten it, this becomes so much difficult. Now I have also learnt that in the options settings, one can set it to open the toolbar by default and I think this setting should be enabled by default.

Anyway adding this option to the toolbar should only help and not cause any issue.