I have some people who send me corrections via PDF annotations and notes. Neither Evince nor XPDF fully support these. Highlighted annotations particularly, Evince shows the highlight but doesn't show the annotation text (no icon to show it, hovering doesn't do anything either). I need Adobe Acrobat Reader for that.
My Poppler is a bit out of date, though it's not clear to me whether more recent versions of Poppler support highlighted annotations fully:
Google Docs has the same behaviour for me as Evince on annoted-highlights: shows the highlight on the text, but doesn't show or provide anyway to view the associated annotation.
Edit: Remove IIRC - justed tested Google Docs again and that's the behaviour.
My Poppler is a bit out of date, though it's not clear to me whether more recent versions of Poppler support highlighted annotations fully:
https://bugzilla.gnome.org/show_bug.cgi?id=583377