my office use it... so far so good, if no external distribution (like share doc with 3rd party) i think it's as good as ms-word. btw, i think most people tend to use 10% of the functionality of this apps.
its is actually... running a laptop with Red Hat Linux... comes with openoffice.org... it can work with all office documents... The writer can save .doc files all the way to Office XP and Calc will do the same for Excel... Presentation, well, haven't opened it b4 so i dunno about that...
I've been using it for over 12 months - writer and calc (On RedHat Linux) and annying my Microsoft using collegues by storing the 'master' copies of all my work in oo format which Office can't read. (But easly could is M$ so desired, oo format files are just zip files containing several easly parsed XML files...) Only the finished versions of my work are exported to M$ format for their consumption.
My only gripe is that the Mac version is behind the Unix/Win32 versions. The OSX version also run's under Xwindows and not Aqua so the look and feel scares off Mac people. (Half my office uses MacOSX the other half Windows and I use Fedora Core 2)
A friends partner has written a book on how to use oowriter. (I've not however seen her book...)