Reading through some scholarly book reviews in the American Historical review and Russian Review, when I came comments on a recent book by Kevin Platt, Terror & Greatness: Ivan and Peter as Russian Myths. From what I could gather, and I don't intend reading the entire book, the argument was about how Ivan has evolved through Russian history as "the terrible" while Peter has come through as "the Great" even though both expanded the territory of Russia, both killed their sons, both came up with alternative internal regimes, both spent a lot of money, and so forth.
You can look at Russian intellectual developments, really since the reign of Aleksandr I, and trace how the outlook towards these two tsars evolved through to the Soviet Union (I think that the book ends with the films by Sergei Eisenstein), and I am guessing that one is trying to explain why Peter is positive (the great) while Ivan is negative (the terrible).
It is kind of interesting, but first you should remember that there already was an Ivan the Great (Ivan number 3). So you really can't have two Ivan the Greats; much too confusing. You should also realize that I avoided the course on medieval Russian history when I was in grad school--too much Church Slavonic--so I am not as familiar with the reign of Ivan IV.
Second, you will also recall that Pushkin, Russia's poetic soul, did not have an altogether positive outlook on the achievements of Peter. He was far more ambiguous in assessing Peter's legacy.
Third, it would be interesting to apply some modern technology tools, such as content modeling, to examine attitudes towards these two rulers in contemporary Russia.