oh I wish some of you would lose the hysteria...
GF might not work for all, and when I was pg, I tossed the book, thinking i didn't need anyone telling me what to do...
But 4 weeks in, and totally on my own, DH very lazy, hands off, mcp, my Mum not 'ready to be a GM' (I was 38 FGS, when exactly did she think my turn would come?), I turned to GF.
I followed her principles, and within days my DS was sleeping, happy, and thriving. Til then I'd be lucky if he slept more than 30 mins at any one time...
Structure and order is needed in some way by all of us, none of us like a life of freefall chaos.
The removal of surprises from a little babies life has to help somehow, to manage expectations with subtle triggers etc... it made sense to me the moment i started doing it, and what's more it worked. (for my DS).
Once the framework is established, you can move timings about, and as long as you make sure that the quantity of time for sleep and rest are more or less maintained, it'll all be fine.
I'd recommend it to anyone to give it a try, get a routine that works for you and broadly stick to it, it needn't be GF exact timing, it's about what works for your DC and for your family.