In my experience as a Roman-turned-Eastern - having traveled through the Byzantine tradition and now comfortably settled in the Maronite tradition - I feel I can confidently say that there certainly is somewhat more of an emphasis on God’s mercy in the East than there is in the West (at least in the pseudo-academic, neo-Thomistic West).That being said, among those of the “John Paul II Generation” in the West, there has been a growing emphasis on mercy, fueled in large part by JPII’s popularizing of the Divine Mercy message; and possibly also by the growing devotion to St. Therese of Lisieux and her “Little Way.”
That being said, there are also many in the East who have a more “fire and brimstone” approach to spirituality, as in the West. They prefer to talk of God’s judgment and think of salvation merely in terms of “avoiding hell” and “going to heaven.” There are those who emphasize the rules, and are quick to admonish others (either behind their backs or to their faces) when they step out of line.
Lest we think that this is a new development in the Church, the Book of Steps (which dates back to the 3rd Century) warns against a spiritual class of folks the author calls the “spiritual ill,” and whom he puts in a lower category than those who are completely ignorant of the Faith. These are people who, today, we’d likely define as having a “Pharisaical attitude” toward the Faith.