Grading comment sheets or checksheets give teachers and students two advantages over free-form grading:
Grading sheets of some sort assure that teachers will give students feedback about all the major criteria they set out on the assignment sheet. Even if you decide to use a simple checksheet that ranks students' performance on each criterion on a 1-10 scale, students will be able to see quickly where their strengths and weaknesses are as writers for this assignment.
Grading sheets, particularly checksheets, typically save teachers time. Even composition teachers don't comment exhaustively about each criterion for each assignment; so, too, disciplinary teachers should be aware that they can comment at some length on just one or two points (typically the major strength and the major weakness) and then rely on the checksheet to fill in for less crucial areas of the paper. If students are concerned about getting more feedback than the checksheet provides, you can encourage them to come to your office hours or send you an e-mail query.