I've used all three. Office 2007 on school computers, the iWork trial, and Office 2008 for Mac. Honestly, I like Office 2008 for Mac the best. I mean, all of them have their pro's and cons, but mostly for compatibility (and thus, ironically, ease of use) I used Office 2008 for Mac the most. Sure, I liked iWork, and it is cheaper, but I was used to Office. And with school, I got the copy of Office for free. (It certainly beats OpenOffice or NeoOffice at that price point. Paying full price for it would be difficult.)