I agree in the case of the Windows/OS X environment, where brand awareness of LibreOffice is low, but in the Linux world... my distribution (Debian) doesn't even package OpenOffice, and I don't know any Linux user who uses OOo.
I think that's when a lot of users moves to LibreOffice.
I have not had any round-trip editing problems flitting between the two under Linuxen of various kinds.
Pleased to meet you. Now you know at least one.