The book is really fantastic. Its main focus is to create a reliable system for tracking projects. If you have a trustworthy system, you don't have to try and remember everything you need to accomplish. It redefines projects and goals and work-steps to make gaining progress a straightforward and easy thing to do. It outlines work flows and assessments of projects and incoming information so that a person can quickly and consistently handler it without anything important falling through the cracks. Some of it is pretty straight forward, like read and assess every email as soon as it hits your in box. Catalog it if you'll need the info later, respond if it requires a response that will take less than two minutes to complete, and delete anything you won't need again.
What I'm happy to see - because implementing many of his operations could suck fiercely for the disorganized - is that I've naturally evolved into about half of the efficiencies GTD suggests. Like I have 20+ rules in Outlook to categorize email for me before I even get the notice of a new email. All I have to do is read and respond as needed as it is already located in an easily retrievable space.
What I dislike is that I want to take the time to create the missing part of my system now. I've got notices and reminders and plans of actions for much of it but my brain won't let it go. I couldn't sleep last night for all the neat processes and spreadsheets I want to make to do this. I am, in fact, unable to fully trust my current system because I know it is flawed in some manner - notable because I forget to do certain things (like buy corn) I plan to do. Grrrr. Annoying.
Now I'm plagued by my desire to organize my organization.