Short-time lurker. From the research I've done, Chicago seems more hospitable to work done in visual art, theory, and poetics (not that Cornell isn't!). The theory lean at Chicago is observable even in the interesting committees assembled (Committee on Social Thought/ Committee on the Conceptual and Historical Studies of Science). My sense is that you would have the opportunity there for a lot of interdisciplinary interaction around your interests, specifically. Of course, both schools are prime choices. It might be worth doing some more research on faculty members/ grad students in your field and related fields at both schools to see what sort of work is coming out of both schools and to get a sense of which might be a better fit. Just a suggestion.
Just a word re: the School of Criticism & Theory. Cornell is home to SCT at the moment (it has happened at other schools in the past), but it is a loose affiliation at best, and lends the program a sort of "prestige" it might not be attributed if conducted at another school. I was at SCT this past summer. I attended with just a CDN MA. It is mostly attended by doctoral students and post-docs (from all over the place-- the program prides itself on being a site for international collaboration). It is an incredible way to spend six weeks. In response to @Warelin on SCT, being a student at Cornell doesn't guarantee you a spot, but there were a few Cornell students that participated when I was there. I got the sense that a lot of Cornell students take the opportunity to get out of Ithaca during the summer, and skip over to more happening cities, however. Given that it takes place during the summer and that most of the seminar faculty are from other institutions, one has minimal contact with Cornell as an institution itself, besides having limited access to the resources and being able to chill on the beautiful campus. I didn't apply to Cornell this year. I did apply to Chicago. My thought, having spent time in Ithaca, is that you should bear in mind that Ithaca is a super-duper small city. I'm not sure exactly what the Chicago campus is like, but as someone who has spent the last 7 or so years living in a large-scale, multicultural metropolis, Ithaca-living would be a tough shift to make full-time, even while it was a gorgeous reprieve. It is a good place if you want to completely dissolve into your research with minimal distractions. I have a friend finishing his PhD at Cornell, and, finally freed from instructorships for a while, he is writing his dissertation in NYC this year, because "four years in Ithaca is plenty, thanks." Definitely consider whether you thrive in a city or would prefer a sleepy upstate town to do grad work in. That would be at the forefront of my mind in deciding between Chicago and Ithaca. They are both wicked schools, friendly to theory, with incredible resources. Also, if you go to Chicago, you will have an equal chance of being admitted to SCT as a student at Cornell, so you could still experience Cornell in some capacity over the course of your grad career. Good luck!