I would think that this book would be weak without his intro and final part yet you should consider them nothing more than an advanced level. I would read the book all the way through. But just pull out as much of his tips and tricks that you can turn into a system that you trust. If it works for you, you will welcome the pain of reading the rest of the book when the time is right. It is so painfull to read because the enormous brain dumps that result are exhausting to get out and you will not really get the importance of his discussion until you have everything out of your head from a real mundane action list standpoint.
I have read the book four times and the last section points, while they seemed wordy the first couple of times, are rather motivating once you are strongly understanding the function of his system. I like the marketing tone because it is catchy. And as I give advice to those friends and family who vent management issues to me, his word choices are catchy enough to remember. I find I always have an answer now on the tip of my tongue to empathize with other's gripes on productivity issues.
His take on Multi-tasking;
-Well, at first I implemented the system to my disadvantage at work in a one item at a time way, and other's around me did not like it. In my head I resisted changing, because I believed I could get it all done with my system. Yet since my job was somewhat secretarial, that did not fly with my superiors.
-Then, after reading the book again, I realized I did not understand precisely. You can not choose your next actions just by any intuition. You need to assess constantly many variables in choosing your next action. And should those variables change in an instant, you need to "refocus rapidly" and your intuition will assess and reevalute your next action.
-In essence, while you are not mult-tasking because you are still only going to do one task at a time, you have renegotiated your next action. And no one in your world needs to know except yourself that you are not multitasking. You bookmarked your next action so you know where you left off in what project you thought was the best thing to work on then. But you renegotiated your next action for whatever your reason. Do what you need to do now, but at least you know what your next action is on that other project so when you return, you do not even have to ask, "Now, where was I?".