Time management is like dieting - every week there's a new fad and someone claiming to have the perfect system. I don't think the problem has anything to do with which system you use. I think we just get the whole concept backwards. We tend to think of time like stretchy garbage bag: if we are careful, we can find some way to shove more junk into it.
But it isn't really about time management at all. Time will roll on its merry way without any help from you. No, it's really about attention and energy management.