My mum and a friend of hers have both done it, just not "religiously" if that makes sense!
both have lost weight, the friend is doing it more so properly, lost over 10 kg over about a month and a bit, also joined a gym but only goes sporadically.
I'm pretty sure he did the extreme start thing, then just tries to stick to the maintenece plan...when he wants tolose a bit more he does the kick start thing again.

Mumis slowly but surely losing the kgs, only doing a bit here and there. definitely makes me interested in giving it a shot.
There is a cookbook too I think..