My major source of reference in questions like this is the book by Prot. Fr. Alexander Schmemann, titled "The Historical Path of Orthodoxy" (its Rusian original, which I read, is here, http://www.wco.ru/biblio/books/shmeman1/Main.htm
). Fr. Alexander seems to be very critical to both sides, the Raskol'niks (those who went into schism because they did not agree with Nikon's reforms), and the "Nikoniane" (those who pursued the reforms). Nikon was, obviously, a troubled person, a megalomaniac who was obsessed with "things Greek" and hated what he thought was a "Russian perversion" with all his heart. His helpers, those who actually made the reform happen, were at times not terribly literate and used the help of very questionable "Greeks," occasionally even plain con artists who made an impression of "learned men." On the other side, there was a lot of fanaticism, and, importantly, messianism, the idea that the Rus' is now the "Third Rome" (as one monk, called Philotheus, put it, "two Romes existed and fell, the third (=Moscow) stands, the the forth will never be"), and that those Greeks were all cowards, perverts, traitors, etc. etc. etc.
The saddest thing was that the whole battle was about the RITE,
not about the faith as such. Neither of the two sides looked anywhere deeper.