It is worth the effort. Initially it does take a number of hours and you start off with a huge list. (I had 200+ items.) Whilst it is time consuming you do get a sense of relief after you have finished. From that point on you capture things as you think of them. I have a series of notepads around the house and work. I write things down as I think of them. Put them in Toodledo either via the iPhone or online and through out the bit of paper.
Dump your thoughts first then go back and sort them into folders and add contexts.