I read a review in Maximum PC between OpenOffice and Microsoft Office. Microsoft Office won, but MsOffice has so many utilities that most average users don't use, and being that MsOffice costs about $500 (US dollers), and OpenOffice is free, average users might choose it, if it was well known, over Microsoft Office.
I had OpenOffice, I liked it, it had some programs that were similar to MsOffice, except those programs made for more advanced users. Only programs I ever used in MsOffice was Word and Excell, so I wasn't willing to pay 500 or anywhere around that for that type of program when Open Office was FREE.