One last note: I'm not trying to sound like I'm diminishing the MFA as a degree. It's probably more rigorous in a lot of ways than a lot of MA programs out there. It's just a very different degree than the MA, which is of course of the same subject matter as the doctorate in English/literature.
MFA programs vary widely. Many MFA programs today are "studio-academic," take three years to complete, require as many lit hours as CW hours, and readings in the third year. Such models are completely different from the traditional Iowa studio model.
To the OP--have you considered a PhD in English w/ a creative writing emphasis? If creative writing is still your primary area, you might want to consider this option; if not, ignore the rest of this post.
Currently, I'm enrolled in such a program. I still have to take the same number of exams as lit students (from the same choices) and still have to take the same number of core lit hours (from the same choices). I will be qualified for many of the creative writing/lit combo jobs that are now advertised. Why would I want to write a dissertation outside of my primary area? I’d lose valuable writing time. This degree allows me to take lit exams and lit hours while still producing "scholarship" (for lack of a better word) in my primary area.
What a lot of people fail to realize is that most "creative writing" jobs today are not 1/1's at Iowa or Irvine; most creative writing jobs are gigs at SLAC's and regional universities, where the person is hired to teach creative writing, generalist lit, and some comp.
Basically, the PhD in English/Creative Writing will qualify a creative writer as a generalist.
Are you going for a PhD in Lit to specialize in a particular area because you're truly interested in that area and could see yourself specializing in that area, or to improve your chances on the job market? If it’s for the latter, you might want to consider a PhD in English/Creative Writing.