The faster the feedback the more motivated students are. Research shows that high quality feedback is one of the best things we can do to improve learning for students. Go beyond simply giving a grade and help students to be excited about learning. Google Classroom uniquely allows you to provide faster feedback and build deeper relationships with students.
I am a collaborator. Technology should exist to make our lives more efficient and better, it should not be a brick. Spreadsheets and data are not something to be afraid of, they are tools of awesomeness.