I'll be honest, I love Google Drive. I use it on a daily basis. I am able to access it on my Android phone, PC laptop, iPad, and Chromebook. What I love about it, is the versatility, share-ability, and user-friend-ability. (I know the last one is a stretch, but I wanted to stick with a pattern here.)
With all that said, while at the Macul conference, we tried to share document and having a bunch of people trying to use Google Drive all at once across different platforms didn't work well. I didn't want to lug my PC around, so I was forced to use my Android phone because my iPad 2 couldn't keep up. (It is faster for me to swipe my keyboard on my phone anyway.) I never thought I would say this, but Office 365 would have actually worked better between our PC and iPad users. The online version actually works fairly well on an iPad.
I do not prefer Office 365 over Google Drive, but considering that Google does not turn off data mining when dealing with individuals under the age of 13 being compliant with COPPA is more important. Yes, you can get a parent signature saying that students can participate. However, Google is still collecting information about students under 13. Think about it.
Office 365 actually has a pretty good web-based Word document creator that is collaborative much like Google Drive. Students can work together and see exactly what the other is typing. This is great when you are wanting to work in small groups and have students piece together information, peer edit writing, or even have a group discussion over a reading assignment. You can also create folders for you to view student work and give instant feedback.
I've created a set of instructional videos that I hope are not too confusing. Number one, you have to remember that this really is just a new version of Sharepoint. If you want a document to only be downloadable and not editable, you need to specify that in the permission levels. Permission levels in 365 is not near as simple as Drive. It will take some practice getting used to the environment.
So if you are curious about Office 365 and what it has to offer, these videos will hopefully get you going.
Getting Started: Creating Folders, Student Access, and Student Permissions
Creating Small Group Folders
Student Access and Tutorial