OpenOffice entered my office February 2004, as the computer I am writing this with only came with Microsoft Works (I did not want to pay full retail for Microsoft Office while I am still starting up the consulting business). OpenOffice V1.1 just works for what I do make resumes, some letter writing, and some short documents for my consulting business and my wife and daughter's schools.
Speed is quite good except for program startups (but I am being spoiled by the (nearly) instant-on nature of my older PalmOS PDA). I have not seen any problems with document compatibility between OpenOffice and Microsoft Word; I use the OpenOffice word processor to do all my conversions of text and HTML to Microsoft Word.
I found my first defect today chart text reformatting can squish your chart labels if you are not careful (I finally generated both charts after several retries).
OpenOffice V1.1 is well worth a look for those wanting an alternative to Microsoft Office, especially an extensible and Open Source alternative.