I was very important to be able to share documents with Windows users. This goes well with Word, Excel and PowerPoint. All known from the Windows versions and estimated functions work after months of trying without any problems with me. In this point have Numbers, Pages & Co. enormous pent-up demand.
One criticism is the performance for me. My old Windows PC open and edit large Excel files faster with Excel 2007 than the almost brand new Macbook Pro with Excel 2011. Here you have probably cut back. However, the difference is not as dramatic. Second complaint: the not entirely well thought combined Ribbon- and menu structure, which probably results from the compelling Mac status bar partially. Both together results in a minus point.
Otherwise, I've worked very well with the Office package and am very satisfied.
Update after six months:
Sharing of files with Windows users works fine - the vast number of users set up on Windows and also on the MS Office package. Therefore, and this is the decisive criterion, to put on the package of Microsoft.
However, it remains primarily in the relatively weak performance, so sheets with graphics to be opened with a considerable time lag, especially in Excel. At the combined Ribbon- and menu structure, I have gotten used it.
Update after more than one year:
I'm still happy with the Office package and its implementation on the Mac. Although the system tray and the Ribbon-view match not 100%, but written as a few months ago get used to it.
Everyone should watch the reviews and comparisons of the MS Office programs and their Apple iWork counterparts elsewhere such. B. at chip.de once. Here it becomes clear that iWork - unfortunately - can not compete with the "classic" MS Office.