Professor Harrington may be a grad student, but he's a great teacher. He's young and kind of looks like he was a stoner back in high school, but aside from occaisional moments of spacey-ness he's pretty alert and on-the-ball. He's a good teacher and gives a TON of clearly typed out materials and due dates explaining his assignments. Everything is also uber organized on courseworks. He's pretty clear about what he wants and doesn't want, while providing you with plenty of creative license. He likes that sort of thing, so if you got it, flaunt it.
His feedback is detailed and really perceptive and he's extremely available during office hours. I went to his office hours actually believing he could help me, which is more optimism than I usually have for fixing my writing issues. He will help you become a better writer if you don't resist him and he allows plenty of revisions so that you've got ample opportunity to get that A or A- if you're willing to work at it. Don't expect As the first time around, though. He's a surprisingly harsh grader, given how laid back he seems.