I think there is a lack of serious understanding of Torah when one is not proficient in the school of Rav Haim of Brisk.[i.e., the sort of deep learning that Reb Haim was known for.] That had a beginning with the Mishna laMelech but was laid aside for a few hundred years as the later authorities concentrated on Tosphot. But now I think that to really have any kind of decent idea one needs to be proficient in the Chidushei Reb Haim, Reb Shimon Shkopf, the Birchat Shmuel [the two students of Reb Haim], and the Avi Ezri.