I am applying to a schools these days. I took the MGRE in October, and I could only manage to get a 600 (37%). I drafted a statement to explain why I struggled with the exam, and why I think the exam is not an accurate reflection of the abilities. Should I bother sending this statement to schools that require the exam? I won't, probably, send the scores to schools that don't explicitly require it. I may send it to schools that recommend the applicant submit the scores.
I'll be more than happy to share the content of the statement via inbox with you. Please let me know.