Im a very go with the flow mother when it comes to Bays routine and he only has one really because he made it up himself!!! from a really early age and is still in the same routine!! i have tried to snap him out of it now he is older because hes still having 4 hours sleep a day and to be blunt - its getting in the way of trying to do things during the day! because he HAS to sleep! if i try to keep him awake hel just go to sleep with a mouth full of dinner in a rediculous place at about 5pm!.
I definately think that its personal preference and whatever suits your child best. I dont disagree with any of the methods mentioned and at some point have used them all myself such as the CIO method - we used that when getting him use to being in a big boy bed. It took him a week and he was right as rain and never looked back.
We did the cosleeping thing when he was a NB till a few months old but not for any particular reason just how it turned out (im a very lite sleeper though).
I guess you have to wage whether your child is going to be differcult to snap them out of the habit, my sister would always put her son in her bed and never let him cry and alway hickyhickyed him and now he is almost five and i kid you not - he is still sleeping in their bed and waking 2-3 times a night crying and wanting attention!!!

i really couldnt deal with that but cant give her any advice because (judge me if you will but) my son was an extremely easy baby who slept 9 hour nights from day 1! and it has nothing to do with what we have done because my DH was exactly the same as a baby so he is just like his dadda.
I also know that Astin will not be the same as Bay so therefore would have to eat my words of advice that i had given to people which is why i try not to give advice in stuff like that.
My only advice is to do what suits you and take plunket and the likes of - reccomendations with a grain of salt as there always seems to be 2 sides to the debate.