There is quite fresh functionality in Google Drive which is very usefull. It is activity stream. Thanks to acitivity stream we have easily accessible information about what changed in files and folders of Drive. Panel content is changing based on context you are in. If you click on file you will see tream of actions taken on that file. It is really great way to see who is working on which files.
According to survey carried out in USA and EU among 500 IT professionals by Spiceworks:
When it comes to approved apps, 60% of businesses said employees are using Office 365 compared to 59% for Google Apps. But for unapproved usage 78% of businesses said employees are using Google Apps compared to 41% using Office 365.
So users by themselves choose Google Apps – is it simpler for them? On the other hand I think decision of companies about using Office 365 is driven by their adoption of Microsoft technology.