i think one should divide the time half for iyun [deep learning] and half for bekiut./fast learning. even though in the conversation of rav nachman 76 we find the emphasis on jut saying the words as fast a possible and going on, in the LeM vol I ch 78 we see that the main thig is iyun. so clearly there need to be both. but how much of each. i can see the need for both -especially in early ages because when people do not get ''how to learn'' [how to really get into the depths of the subject] they never get it.
when i was young i also did not understand this as i think most people do not. i thought what is the point of spending a few weeks on one page of gemara when i have not even finished the whole tractate at least a few times to get the big picture? but now i see that we people do not get iyun when they are young they never get it. o clearly the great litvak yeshivot that immerse people in iyun right away have the right idea.