How I Use It
Like many schools, we initially moved to Google Apps to better manage our email. As a technology integration specialist, I have been showing teachers all of the benefits of the entire Google Drive suite. It has been great for drastically reducing the amount of paper that we use as students are now doing a lot of their work in Google Drive (or uploading Word docs), and sharing them with teachers or submitting them via Edmodo and Schoology.
We are also implementing a BYOD program in the high school, and Google Drive is great since it's platform independent and has great mobile apps. We don't have to worry about kids purchasing machines without office installed and/or not knowing how to install and set-up other office suites.
I also use it in a class I teach to 8th graders (computer applications and digital citizenship). It works great for teaching them basic skills that the high school teachers say they want them to have (word processing, data analysis, creating presentation, etc). However, as a former math and science teacher, my biggest complaint is that when creating a graph in Google Sheets, I can't show an equation and add a trendline. This is a big deal for doing labs in physics. My hope is that there will soon be a third-party app to address this.
Google Drive is an awesome alternative to MS Office and other open-source alternatives like LibreOffice and OpenOffice. There are still a few features that make it lag a little behind those office suites, but with Google's recent introduction of third-party addons for Docs and Sheets (documents and spreadsheets), Google is quickly catching up.
It has been invaluable as a collaboration tool for both students and teachers. It integrates with both Edmodo and Schoology, and best of all, it's free.