I also voted no. Like dabots, I'm not very familiar with the grading system. Could someone perhaps explain it a bit more?
Though my circumstances were no doubt different (I was applying to NYU PT), I also considered addressing my less-than-stellar GPA (3.1 from an average school) in my optional essay. I also did not have a great GMAT so I thought academics may be an issue. Eventually, as the deadline got close, I decided against addressing these perceived shortcomings in the last essay. I felt that highlighting a negative attribute in my profile as perhaps one of the last things the AdCom read could not possibly help. I had no compelling reasons for my GPA issues though I did show improvement as I got older.
I used the optional essay to stress the positives in my profile (W/E & extra-cirrics) and reinforce my interest in the program...almost like a cover letter of sorts. It worked for me; I was accepted last month.