I have been using Mendeley as a reference management software for more than seven years and was an excited user - nice usability & GUI, open access, good integration with Word, a simple but effective Web-Importer, etc.
After Elsevier bought Mendeley, things gradually get worse in terms of functionality and usability, and after several moments of frustration I finally decided to quit using it.
What are decent open access alternatives with good usability and team/multi-user functionality?