I am also in the same situation-- although i'm leaning towards Cornell, I just got a letter in the mail from Pitt offering an absurd amount of academic scholarship money-- in addition to need based grants. If Cornell cannot match this, then it would be difficult for me to turn down Pitt.
As far as my decision making, a couple things are important to me. Match Possiblities, Research, Location, Curriculum, and Fin aid (in no particular order).
I haven't seen a match list for Pitt, and while i'm sure its excellent, I extremely impressed with Cornell's (people matching in Derm, Optho, and other specialties at top centers in the country). That said, I do feel its difficult to compare match lists of schools in the top tier-- too many variables involved-- = Toss up
In terms of research, UPMC is renowned, its one of the better established and most comprehensive med centers in the world. Pitt student's have access to that and whaterver resources its undergraduate campuses have to offer. Alternatively, Cornell has the powerhouses of NYP, MSKCC, HSS, and da Rock. In my particular situation, I went to undergrad at Cornell and through those networks have been able to communicate and form relationships with investigators at many of these institutions-- thus I kinda already have a foot in the door I guess at Cornell for competitive research. (Is this reasoning valid? Please keep me in check here...) = Point Cornell
Both schools have PBL, from my understanding, while Cornell does market itself as all PBL, it is in fact probably 30-40% of a day's work, as lectures, labs etc are among the daily routine. Classes are graded h/p/f, which I don't necessarily mind-- I hear that people aren't competitive so the honors doesnt get people bent out of shape. Also, Cornell gets out of class ~1pm. Pitt on the other hand does have pbl, I suspect its on par in terms of commitment with Cornell's, but just that they don't market it to being that way. Also, from what I remember, they have the first two weeks of anatomy, which I think is pretty cool.... (anything else i'm missing here? Current Pitt students?)
= Toss Up
As far as location, c'mon, let's be real. Manhattan>>>>>Pittsburgh. In terms of cost of living, Olin Hall is $500/month. That is absurd. Also, in med skoo we'll be able to find free meals readily avaible on a daily basis at both schools. I think that living frugally and spending prudently is more of an individual discipline question rather than blaming what is an expensive city. If you want to live cheaply in manhattan, it's definitely doable. = Point Cornell
As far as fin aid goes, I find it difficult to simply believe that one school is better than the other based on avg. Grad indebtness, the values calculated in the msar leave out a number of variables that may be and are often important to many people. I think its best to compare fin aid packages once you get them from the school. Right now for me Pitt is winning in this category, (I haven't received my package from Cornell yet) though I find it difficult for Cornell to match Pitt's scholarship. = Point Pitt
Sorry for the long response, I think this was meant more for me to rationally step through this decision making. Notice, the lack of usnwr ranking mention. Please people, do not use rankings to make decisions about schools-- you're stunting your medical education if you choose to do so. Remember, rankings and prestige do not save lives! Good luck. Oh and Pre-Pitters, how was second look weekend? I wasn't able to make it up....