This chapter is fairly well written and integrates the ideas of meristematic activity and cell growth.
The section on multistep meristems is a new concept in botany textbooks. This is an important concept of rather recent thinking. The role of "quiescent centers" finally makes some sense as reservoirs of realtively early-generation cells lacking accumulated somatic mutations. The "transitional meristems" of this new model used to be called embryonic tissues or primary tissues.
One disappointment I have with the text here is Fig 12.2. It seems that the zonation of the meristems is not even mentioned. The micrographs are too close-up to show the zonation, and micrograph B shows an internal layer of the root cap as the root apical meristem. This is an error that will likely be fixed in a later printing. Fig. 12.4 helps somewhat, but I would have preferred the labels on a real micrograph.
The section on polarity and cell differentiation is quite nice. It integrates some ideas from protists to concepts in higher plants. These are important ideas that have an awful...maybe awesome...amount of missing information. If you want to make a name for yourself and perhaps even win a Nobel prize, solve the problem of how cells differentiate.
I love the inclusion of asymmetric division in our book. Most cell division chapters in books lead you to think that all meristematic cell divisions produce equal-sized derivatives. Some books even state that unequivocally. They are wrong. Asymmetric divisions are necessary and very important.
The section on plant hormones is very near and dear to my heart. It is in this area that I earned my PhD...studying the role of hormones in the growth of flower parts. The author describes the "acid growth" hypothesis quite nicely, but I have to inform you that that model only explains the initial growth phases (first few minutes to few hours) of any organ. There is a secondary component...sustained growth...that involves new wall synthesis. This later part of growth is also still uncharted territory. There is a lot of room for people like you to make your own mark in science.
The author points out several areas where there is room for you to add to our knowledge. This chapter is an area that is very open to research. If you feel like it is a disjointed collection of thoughts, you are right. Much work remains to be done here...especially in botany!
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