The issue with such system is that it does not allow you to plan for the future on the basis of your priorities and long term goals. It does allow you to get things done, but generally you'll be only getting urgent things done, while important but not urgent things are left behind (learning a new programming language or a technology, practicing) your guitar. Here is one trick that improved my productivity much and allowed me to concentrate on what is important. I extended such system with the ability of weekly planning (and not only review). At the beginning of each week I assign time for each of my project depending on its priority and its alignment with your long term goal. I start by stating my long term goals and my principles, then what projects I am working on, what short-term goals I want achieve. I then assign when and how long I will work on each projects.