Having read Malmuth's poker essays, I was prepared to find this book similarly scattered. But GTOT is a thematically organized book, and contains more material that struck me as theoretically interesting and/or important. At the same time, it contains some material that seems like it ought to be fairly basic, but that I haven't seen anywhere else.
The first section on non-self-weighting strategies is interesting, although I don't particularly like this way of looking at things. However, it's possible to read the section and mentally translate everything into your own frame of reference.
The second section contains a lot of material on standard deviations, bankroll, money management, etc. In places it's dry (it's hard to spice up a formula), but it's important to develop some working familiarity with the ideas he presents here. Some of the conclusions he draws are quite surprising, and any aspiring player should make the contents of these chapters second nature. The more experienced and more mathematically sophisticated reader will probably take issue with some of the assumptions his models make (e.g., that hourly poker results are independent and normally distributed).
The fourth section (written in part by Mark Weitzman) covers tournament strategy. While I haven't read any other books on tournament strategy, what Malmuth provides here seems like solid advice, and at the very least, a line of argument the tournament player should be familiar with.