I would like to add the sole reason that makes me install it in my computer:
OpenOffice is a great for opening corrupted files that otherwise brutally crash Microsoft Office applications.
This i what I usually do when I have a problem:
- Setup OpenOffice.
- Open my corrupted file.
- Save it, usually with all content intact.
- Uninstall OpenOffice.
The moral of the story is that, for Microsoft, having such a high quality, independent implementation of their file formats is a plus.
I understand and, to some extent, agree with many of the reasons exposed in that article, but I must admit that it is not use for me to switch to a different product. I like Microsoft Office, and I know how to do my work with it. If my everyday environment weren't Windows, I would probably think different. If I worked for Sun... you bet! ;)