Thank you so much, sdklos, for your vote of confidence. I hadn't thought about it this way and your comments help add perspective. Here's more info:
School A (which I chose):
private
equal overall rank as school B but better reputation in my particular literary subfield, hence potentially better job upon completing
a lot more money (about 24,000 for four years, plus 19,000 in year five, this includes a competitive university-wide fellowship)
a lot less teaching: no teaching in first two years, small classes after that, only teach comp once, greater focus on courses you design
less of a fit with the literary research interests I always thought I'd follow, but already have an adviser clearly lined up who is connected to a previous adviser of mine and comes highly recommended. She is willing to work with me on old focus to some extent, but also expects me to branch out into new goals stated in SOP (Fear: what if the intended diss. topic they're all so game on doesn't work out? Do I have a fallback?)
less classes in the interest I thought I'd follow + more interdisciplinary work expected
better climate
scary future committee member in a small department where personality issues have greater potential to metastasize
School B:
state
less money (17,500 in the first year, about 16,000 years 2-6)
significantly more teaching: grading for up to 50 students in each semester of the second year, teach comp. at least 4 times
"the one" - a woman another department who focuses specifically on my older interests, albeit across disciplines. I am familiar with her work and teach her stuff in my classes. Very amenable to working with me, but other committee members in home department are considered weak in my subfield, so potentially poorer job upon graduation. (One member was so young she had never chaired a diss committee before, which would require co-chairing by the woman in the other department)
less demand to develop the new interests which might, actually, prove more viable
more classes in the old interest I thought I'd follow
bad weather
large program where the focus on individual students seemed less of a priority
a dearth of students in my subfield
Basically, this all comes down to research, I think. The old stuff I love and the new stuff I now really must do in order to survive at school A. It's freaking me out to be taken so seriously with no research plan under my belt. It's making me sad to feel I have to move away from the literature I always loved and thought I would specialize in. But it would also make me sad, I think, to go to the less prestigious school where I'd be just one in a crowd when I worked so hard to get into a top place. I feel torn.