To learn fast [saying the words and going on] or slow [with review]? I had seen the fast way in the Musar book אורחות צדיקים Ways of the Righteous and also in some book [בניין עולם] in Shar Yashuv. [Note1] But in Shar Yashuv itself there was [as in all yeshivot based on the Gra] an emphasis on slow painstaking review.

[There was recommended to review everything you learn ten times] 

At the time, I came up with a sort of middle path or review twice. But over the years, I have found there are places where the fast sort of learning seems to work best--I mean absolutely fast. And there are places where review is the only thing that works. 

The places where fast is the best is where review does not seem to work at all. I am sorry to admit it, but an example is higher mathematics. Places like that where review does nothing (since it is like a vertical structure), there I need to get the whole picture before I can understand even the slightest detail.

Places where review seems best are in Tosphot or books of Rav Chaim of Brisk or Rav Shach. These are places that are deep and profound, but do not depend on extensive knowledge elsewhere. That is to say--they make sense in their own place--if you spend enough time on them.