I'm a developer, and I use computers in a way that gives normal people (including developers) the heebeejeebies. However my use of office stuff is relatively rare and extraordinarily basic - I would say pretty close to the majority of users' usage. There are no problems with libreoffice for that kind of usage. In some respects for people not hunting pointless features it's usability is better.

I have some legal and administrative issues at the moment that require me to share office docs fairly regularly, as well as editing PDFs for filling in forms. I have had no collaboration problems at all with either of these activities exclusively using libreoffice. At one point I tried out the online versions (google docs / office 365 online) and it was a disaster.