Great question. I purchased iWork 09 cause it was cheaper and because I don't use Excel or Word very much. I have no problem opening those files and sending them but I think I miss some of the features of office that made it easier to use for me. So while I'm glad I saved $50-$60, sometimes I wish I had dropped the extra coin! But the more I use it the more I may find work arounds. I've only had a Mac for like 1 1/2 months.