I actually do find 'todo management' methods to be useful, if only to the extent that they help me figure out what I should be working on right now. When faced with multiple overlapping projects/clients/deadlines, it can be very difficult to keep all this stuff straight in my head.

One of the most useful 'todo system' concepts I have encountered is the notion of 'hiding' a todo item (i.e. keeping it from distracting me) until it is relevant [idea from http://bitliteracy.com/, a book by Mark Hurst]. For instance, I shouldn't need to see anything about filing taxes on my todo list every single day of the year—this shouldn't show up until the relevant time. The OP's method addresses this with the 'weekly' and 'monthly' lists that are read less frequently, allowing reminders to become daily only when they are relevant. The system Mark Hurst designed (http://goodtodo.com) instead allows you to specify a sort of 'start date' for a todo item, and it won't show up until that date. I have found this idea, however implemented, to be very useful in allowing me to get things out of my head and into an organized system, but not let them distract me until relevant.

[Full disclaimer: I have no connection with Mark Hurst other than having read the book linked above and attended one of his talks.]