Online office suits or platforms used to be limited to Google, well now Apple has release iWork in Beta which is free right now. I have used Google Docs before but not heavily, I have a subscription to Office 365 as part of MSDN which I am trying out now also.
I started using Office 365 about a month ago, but not heavily either. I use SharePoint for work and save my documents there which i like a lot. Office 365 is the same thing, but it is not contained to the private network. There are ways of further securing Office 365 using SkyDrive Pro, but for the time being I am using the version I have as part of my standard subscription. This is secured to the people that I share the documents with but it is stored on Microsoft servers which does open up issues with certain country specific privacy laws.
The user experience that Microsoft provides is very closely matched to the installed software which is very impressive, also part of the subscription provides the install software that will contact to the Office 365 Sharepoint Document Library.
I am going to work a little more heavily with all three of the platforms and record my thoughts and comparisons about each in future posts so stay tuned.