Getting Things Done was an eye opener for me. Writing down all of your open loops really freed me. It allowed me to become more organised and helped reduce stress.
One aspect that I am having issues with, though, is having too many priorities. The GTD system prescribes that you look through all of your projects and decide the next action for each. This helps you get organised and see all of your projects and open loops. The problem, for me, is that it doesn’t help you focus.
Warren Buffett supposedly give one of his employees a lesson about priorities. He told his employee to make a list of his goals. He then told his employee to throw them all away apart from the 5 most important. This flies in the face of GTD.
Spreading yourself too thinly prevents you from making big progress in any one area. Spreading yourself too thinly means you are good at many things but a master of none.
Dispite this, I still think it is a great book. I would encourage you to read it for yourself and make up your own mind.