This isn't even a contest. The world uses Microsoft Office for Windows, and the only thing that is fully compatible with Office is... Office.
True - most of the time. There are times when moving docs from Mac<->Windows version of Office will result in problems, for example, such as corrupted tables in Word or text font size changes in PP. Even going from one version of Office to another on the same platform can cause incompatibilities or problems.
It doesn't matter whether iWork is a nice suite of applications (it -is- nice). It also doesn't matter that OpenOffice.org does almost the same job as Microsoft Office FOR FREE.
What matters is that none of the alternatives work well enough in the real, networked business and academic world where people DO exchange documents with each other. And iWork and OpenOffice.org most of the time hopelessly screw up text formats and other settings of a document.
Here I disagree - OO can be used in an undergraduate environment quite successfully. Most documents are simple papers / presentations with very little complex text or layouts. OO works just fine, and exchanging Doc files as rtf works well, for example. If you need more complex capabilities then OO or iWorks is less useful in an Office-centric world; but to say "none of the alternatives work well enough ... most of the time hopelessly screw up ... a document" is not correct. All of the tools we mentioned can function well if they are aligned to the task and environment in which they are used.
You don't have to like this. I don't like it either. But life in the business world is easier when you use the same language and tools. And Microsoft owns the desktop tools market. End of discussion.
True. Office rules on the desktop; but that is no reason to end discussion, unless you live north of the Weißwurstgrenze.