Ken nailed it. Yes the method takes longer, but it worth it in the long run.
I would say there is quite a bit of divergence between this and McD. Where McD says to start dropping the weight and kill kill kill, Morrison will actually bring the weight up. The stair step of the weight is really the key and produces a bird that flys at a higher weight.
For me it is a no brainer. Go with a method in a book or go with a method I have never seen fail and consistently produces the best goshawks I have seen, especially when I can learn it right from the horses mouth who has been doing it for almost 30 years. Which I think is the key to imprinting at first... finding someone that you have seen make it work the best and follow their method to the T.