Learning in depth is the major idea of Litvak yeshivot. The three great Litvak yeshivot in NY were known for this. Chaim Berlin, Mir, Torah VeDaat. Also in Israel there is Ponovitch.  I think in depth learning depends on one's mind, or on having a learning partner with that kind of mind. I saw this when I was learning with my learning partner in Uman, David Bronson. He would almost effortlessly see the depths in Tosphot without blinking an eyelash. This had nothing to do with bekiut -- since, in fact, he had not gone through most of Shas by that point. It was all simply being able to see the depths of the Gemara and Tosphot. 

So what does that mean for someone like me? Well, it means if seeing this sort of depth in Gemara and Tosphot does not come so naturally, we must spend much more time on review. 

I admit, I was never able get to this sort of depth while in Shar Yashuv, nor in the Mir. This is the case even though I was exposed to this sort of very depth learning in both places. [I was in the classes of Rav Shmuel Berenbaum aninto the d the other roshei yeshiva], I simply never got the idea. [For myself I simply learned the Tosphot, Maharsha, Pnei Yehoshua and other achronim.] Only later, when I was learning with David Bronson (and saw this sort of depth come naturally to him) did I begin to see the idea. You can see this sort of thing in my little booklet on Shas [which has some accounts of David's approach but also after learning with him and sort of getting the idea --my own expansion of that kind of depth.] Here:    Or better yet look at Rav Chaim of Brisk's Chidushei HaRambam or Rav Shach's Avi Ezri.

[The point is in Torah : to get it right is the main thing.  

of course in all major litvak yeshivot the slow in depth learning is for the morning and the fast bekiut is for the afternoon. but for me there are certain kinds of learning that work only one way, not the other. for example--gemara, i can not get the gemara and tosphot at all without slow painstaking digging in depth. math and physics are just the opposite--i cannot understand a word until i have read the whole book saying the words in order from beginning to end at least four times.  in mathematics--going over what i do not understand does nothing to help me understand. i have to go through the whole book at least four times and then it starts to make sense to me. [see gemara avoda zara pg 19 and the musar book ways of the righteous and conversations of rav nahman 76]