I'm trying to make the same decision and am also curious why UIUC is ranked higher than Cornell. I'm trying not to care so much about rankings, but if Cornell's ranking is lower because of something that will directly impact my graduate experience, I might have to consider it.
The people I've spoken to have said that while UIUC may be more reputable among engineers, the first person who reads your resume at a company might not always be an engineer. In that case, Cornell is a more generally recognizable name. Sounds like reasonable advice, but doesn't tip the scale for me.
