I have not used any MS program since early 2008 (I had been a power user for Excel (Windows) at a Fortune 100 company for 8 years). For a long time I used NeoOffice because it was indeed more Mac-like than OpenOffice. But the free “demanded fee” caused me to back away. I kept it until early this year, but seldom used it the past two years. I have had OpenOffice on my computers during that entire time just to follow progress and giving feedback. About two years ago it was good enough that I finally began using it (when needed). Then with the split last year and the appearance of LibreOffice, I switched to that and use it now. I exchange files (word processing and spreadsheets) with several others, and LibreOffice works most of the time. Keep in mind for these exchange files we do not use complicated stuff (seldom footnotes, bibliography, etc.)
The major problems for LibreOffice on Mac: 1) tables do not make the round trip to MS Office very well, including how the margins are affected; 2) scrolling is still a problem on the Mac; 3) bidirectional work is not complete (I use Hebrew as well as Greek, Latin, German, and English).
For my exchange work, LibreOffice is the one I use most. But I also keep the IBM rendition called
Symphony. (see
Symphony Wiki for many helpful links.) It is actually the most stable of all the various forms (OpenOffice, LibreOffice, etc.). It only has the three main programs (write, calc, impress), so no database. Since I never use databases it isn’t a problem.
For serious writing I use
Mellel, best for my work with Hebrew. I also have begun using
Nisus Writer Pro (native .rtf) for exchanging some files.
I have both Pages and Keynote; Pages does some things I need for page layout that none of the above programs can handle. Also, keep in mind that opening and saving documents in native MS Office formats does not guarantee that all capabilities will go both ways. If that is important, then MS Office is required.