The more I use Numbers and Pages the more I like them. I've pretty much stopped using Word a while back and have been using Excel less and less. Virtually all my personal stuff is now done through the iWork apps and with the latest update I can't se myself opening up an MS Office app on my Mac for anything anymore. The integration with the iPad and iOS7 now is fantastic. For the heck of it I opened an Excel document I use for work in the new Numbers and it looks exactly the same in Numbers and works exactly the same. I also sent t back to Excel and it worked perfectly there as well. I think the days of Office taking up valuable real estate on my Mac Hard Drive are numbered.
If it wasn't for my job being in a Windows environment with MS Office I probably wouldn't even be using Excel or Word on my Mac any longer. The fact that Microsoft is dragging their heels on getting Office to the iPad is another thorn of contention to me making me want to drop them like a hot potato. They truly missed out on a great opportunity by not bringing MS Office to the iPad when it was released 3.5 years ago. I think Apple getting iWork to the iOS was a brilliant step and really made people think twice about sticking with Microsoft. What makes it even worse is that the 3 core Office programs (Excel, Word, Powerpoint) were originally Mac only products and should be the best of the best, but Microsoft wants to treat them like the red headed stepchild and focus entirely on the Windows versions.
I've been a heavy user of iWork. Pages in Layout mode is great for writing short, scientific reports that are heavy in tables and images. Keynote is fantastic for presentations. I'm using Numbers more and more for calculations on moderately large data sets.
Fortunately, I've kept Office versions of all my iWork documents... just in case something like this happened. Back to Office, Dropbox, Documents To Go, and Office Webapps... the same file is editable (and sharable) on all of these.