In terms of Rav Shach's Avi Ezri and the books of Musar of the disciples of Rav Israel Salanter I think it is best to have sessions in which you finish the book in the way of "Girsa" just saying the words and going on. No review]. But that is besides a separate session in which you learn the book in depth. That is you take just one section and go over it many times.
[When I say Rav Shach's Avi Ezri I really mean that whole school of Rav Haim of Brisk and his disciples up until Rav Shach that really showed the depths of Torah.
When I had little time for both a fast session and an in-depth session, I used to learn the Avi Ezri in the in-depth way of going over a whole section once every day until it started becoming clear.
But in terms of Musar (works on mediaeval Ethics) I preferred (because of limited time) to at least once get through all the major works of Musar. So I mainly just read through the classical Musar [Ethics] books. חובות לבבות, שערי תשובה, מסילת ישרים, ספר היראה המיוחס לרבינו תם, מעלות המידות של בנימין הרופא
Obligations of the Heart by Ibn Pakuda, Gates of Repentance by Rabbainu Yona, Mesilat Yesharim by the Ramchal, the Book of Fear attributed to Rabbainu Tam, The Greatness of Good Traits by Binyamin the doctor.
The great thing about Musar is that it gives a good idea of the big picture and the importance of good character. In fact Musar reveals an imporant truth--that without good character traits, nothing else can even begin.
There are also Musar books written after the Middle Ages which Rav Isaac Blazer listed in his book on Rav Israel Salanter.
The Musar "thing" and the Gra and Rav Shach seem imporant to me since I think if one is going to learn and keep Torah at all, it makes sense to do it in the right way.
I say, "Do it right, or do not do it at all."
The way I learned Rav Shach when I was in Uman and was learning with David Bronson was by going over the actual Gemaras that Rav Shach is based on.