Online Grading on Google Classroom

What I love about online grading is the speed of grading. I feel that I can grade faster as compared to using a red pen as I don't need to underline,circle or mark the errors while evaluating. The red marks help me to decide the marks that I will give but I often spend longer time to do that. I know that the students are not usually interested to know the explanation of the errors that they have made.