I would focus Unit 1 and 2, which covers proteins and glucose-related metabolisms, as well as Unit 5 on integration of metabolism. As you pointed out, there's a lot of stuff in here that won't be tested in such details on the MCAT. So use it as a supplement only in addition to the core biochem review prep book.
Some parts in this book are useful. For example:
- page 5: some tricks to remember amino acids (aa)
- page 7,8: tiltration of an aa
- page 9: application of HH equation
- page 11: nice summary of the chapter.
- Unit 1: chap 3 on Globular protein: very nice description of Hb and its relevant stuff in a very concise manner (page 29-32)
- page 81, 89, 92!!!
The book is useful, but not necessary if you already have other sources. I used EK only, thus this one was a nice supplement, especially the summary pages. I don't know much about TPR or Kaplan books, but if you already use detailed stuff like TBR, then no need to bother. I would recommend against using >2 sources for content review; after all, it's the thinking under stress that matters.