I decided to give Office 365 a try so I signed up for the free 30 day trial. I already had Office:mac 2011 on my Mac Book Pro and I had Office 2010 Premium on my Windows 7 based laptop. Office 365 loaded onto the Windows laptop perfectly and the upgrades to the core products and Outlook is really nice. Now I understood that for the Mac it would still be Office 2011. So as recommended I uninstalled my original copy of Office 2011 on the Mac and re-installed it from Office 365. Everything installed nicely and there was no problems installing it. The issue came in where on my Office 365 account page it never showed that I had a Mac installation. It only showed I had installed Office on just the one computer, the Windows laptop. I contacted Microsoft and they said as long as the Mac version works it's good to go and there was no issues. I opened one of my spreadsheets on the Mac and attempted to save the spreadsheet to the SkyDrive - which is supposed to be the backbone of Office 365's sharing abilities. Saved the document to Skydrive and opened it on the Windows PC. I made changes to the document on the Windows version and saved a copy to the SkyDrive. On the Mac I reopened the document after searching the SkyDrive for it because every time you save a document it created a new copy. Every time though when I saved my document, the Windows version would not open the latest version of the document. The Windows version of Office 365 runs beautifully and it communicates great with other Windows computers. It just doesn't want to communicate well with the Mac version. It could be because the Mac is still on Office 2011, which is older and perhaps that will change when/if Microsoft upgrades the Mac version. In the end I cancelled the Office 365 subscription because of the issues I had with communicating between the Mac and Windows environments. It was no where near as easy as their documentation suggested. In fact for the Mac, there was little or no support or documentation available. Even using the Microsoft chat feature with their support line helped because they kept referring to the Windows version when I clearly told them the issue was with the Mac. Their response was basically that the features were not available in Office:mac 2011. So then why continue with the subscription if advertised feature and benefits of Office 365 are not available on the platform I use 75% of the time. I believe that the Office 365 product is really good, as long as you work in an all Windows environment. If and when Microsoft decides to upgrade the Mac Version and bring it on par with the Windows version I will probably resubscribe to the service. Of course I would also like to see Office come to iOS, which for the life of me I can't understand why Microsoft hasn't committed to yet. Until then though, if you already have Office:mac 2011 on your Mac, don't bother with Office 365. You won't be gaining anything except frustration. The "seamless integration" that Microsoft touts between the versions just isn't there.