I've been a GTD acolyte for a few years now and am very happy with it. There is one major nagging problem I have though, and it seems to be rarely if ever mentioned in GTD discussions.
In my opinion, the main source of GTD's power is the idea of having all your projects and life goals, no matter how complex, distilled at all times into one or more bite-sized next actions. However, I often find it difficult to identify bite-sized next actions for projects. In some cases, it takes more work to identify next actions than to actually perform the actions.
A good example is a book reading project i.e., I want to read book X, which has 1000 pages. It's obviously a major project, but what next action can I take to move forward toward the overall goal? I typically have next actions like "read book X for 15 minutes" but that is very unsatisfying and seems to defeat the main purpose of GTD, especially when most of my complex projects end up with next actions like "work on project Y for 20 minutes."
What do others think about this issue? Can anyone give examples of a better next action for something like the book reading project? Thanks for your help.