Help!!!!! Cornell vs. UPenn

“Cornell is the hardest to graduate from…”
Not that hard, evidently.
http://irp.dpb.cornell.edu/tableau_visual/factbook-graduation-degrees
“why do people say…” reputation developed long ago, when it was perhaps more true.
Perpetuated by succeeding generations because it makes them look tough for handling it. IMO.

“…do any of these schools suffer from grade inflation”
http://www.outsidethebeltway.com/grade_inflation_at_cornell/
http://talk.collegeconfidential.com/cornell-university/487570-grade-inflation-or-deflation-p1.html
https://web.archive.org/web/20100214201042/http://registrar.sas.cornell.edu/Grades/MedianGradeSP08.pdf

" Im trying to become a biomedical engineer or something of that sort and work with stem cells and such…"
I imagine what is important is preparation for graduate school, and both of those
places can do that for you. But for specifics, inquire at each school.

".other pros and cons "
Different settings, obviously; Cornell is more diverse IMO
I believe you will have a clear preference for where you want to be/ feel most at home/ after you visit both schools.