@Penn95 : I disagree still
Tier 1:
HYPSM
Tier 2:
Chicago, Columbia, Caltech
Tier 3:
(Penn, Duke)
Tier 4:
(Penn, Duke), Dartmouth, Brown, Northwestern, Cornell, JHU
Note that Penn has lower peer assessment scores than Cornell and JHU (and Duke if I recall correctly), so the distinction between tier 3 and 4 is very small if existent at all. When assessing your own school, you should focus more on what outsiders think; everyone is subject to overconfidence bias.