I had the total opposite experience to some of the members here, my very fussy clingy baby slept zero and screamed 24 hours a day for 4 months - we had a nanny at the time who insisted on CC, and to be honest -by that time, I was desperate to try anything. So we did it, and he got it in the end and ended up being a great sleeper. When DS4 came along, he was such a cruisey baby that I decided to not give him a routine and not CC him, I just a) didn't see the point and b) wasn't completely comfortable with it, he was a great sleeper for almost a year - and then it was like a light switch was flicked - he became a terrible sleeper, getting up throughout the night, drawing on walls, waking up and 2,3,4 in the morning. And I'm sorry to say - he is still like that now - at 3 years and 3 months.
So I personally look back and wished I'd gotten him into some kind of routine. Having said that - hindsight is a great thing And of course, you can only do what you feel comfortable with!