Tried to follow GF from week 6, but gave up after two weeks nearly pulling my hair out. I found I was constantly trying to wake DS up or standing in a dark room trying to put him to sleep.
It was very stressful and felt I couldn't leave the house with DS because he would go to sleep in the buggy at the wrong time etc.
The one I did find useful was the expressed dreamfeed. I've never gone to bed early but because I don't particularly enjoy breastfeeding, I found it a relief hat I knew after 6pm I didn't have to BF again until in the night.
DS has been having a bottle everyday since about 5 weeks, although he did have bottle at around 3 weeks due to cracked and sore nipples.
Having read GF's book, there is a lot of things which seem to make sense but being able to practically apply them to a new baby is difficult. For me, I felt like I had been thrown in the deep end and had no idea what to do with a baby and found that using a suggested routine made me feel like I was able to cope.
I can absolutely understand people who say they've taken GF's routine and adapted it for themselves. Ignore the strict times of day, I follow the general pattern suggested in the book, but if he wont sleep or feed then I don't worry abut it.
DS doesn't sleep through the night, but then I don't think there is anyway you can guarantee a baby will ever sleep through the night, and I hold out for the point where DS learns it on his own, as seems to be suggested on here many times.