Routine worked for me and my dd, but it wasn't a strictly prescribed one - we kind of found our feet together, and she slept thorough by about 5-6 months, by herself.
I found Gina Ford far too rigid, but it did help to try to understand the whole feeding and sleeping thing a little - and dd NEVER went 4 hours between feeds whilst BF - she was every 2-3 hours, so that was pretty relentless.
I could never co-sleep with a baby, as I'd never relax for fear of squishing them - not that it bothers me if other people choose to do it. She was close enough in the moses basket, next to the bed, and she went in her cot in her own room at 3 months (ish), and I think that helped improve her sleep patterns too. Incidentally, I have never minded her coming in my bed since she wanted to at around 2. My DH works away, and DD is now 5, and she'll probably crawl into my bed a few nights a week, which I love!
I missed out on alot of baby groups as I didn't want to disrupt DD routine - it was lonely at times, but it was worth it. I am dreadful with very little sleep - hence my name! - so it worked for us as a family. I would do it again too,although my next one is going to have to fit in with my 5 year old.
I've also seen my SIL not establish a routine, and she's now got a 2.5 year old who sleeps terribly, does the whole vomitting on demand thing to create maximum disruption! I think that they've allowed her to rule the roost - she went back to work when DD was a year old, and they still have her up at 9.30 at night!!! To me, that just doesn't seem like you are using your common sense and thinking about having to get your child up at 7am - unless, of course, you don't mind not having any time to yourself, or with your DH. I know that suits some, and I guess some kids do need less sleep.
I don't believe for one minute that small babies can manipulate - it's a ridiculous concept.
At the end of the day, we all should do what feels right for us, but it must also be practical and workable for everyday life.