How long is the transformation period for a GTD´er?

I heard from someone I´ve been using GTD for half a year but I´m still struggling with my life" - 6 months is no time :-) I´ve been using GTD/7 Habits principles for about three years now and I´m feeling now that I have transformed from a reactive to a proactive person. It took some disciplined work but I believe there is no shortcuts.

One practical thing that helped me out in my planning was moving my weekly reviews from Sunday evening to Friday just after lunch. By that I can live disconnected in the weekend and my mind is peaceful knowing what to do when the work week starts.