I've been working with ONLYOFFICE for almost a year and really love it. I appreciate its really convenient document management system and a bunch of features for collaboration. We share our docs, co-edit and comment them - it's an essential part of our work as we usually write articles together. Since we tried ONLYOFFICE editors we don't want to return to Google Docs.
Recently I've found another tool that helps me a lot - ONLYOFFICE Calendar. I plan everything with it and get notifications about what I have to do so I've freed some space in my mind for more creative thoughts :)