It went against my instincts but my now 2.3 yr old DS woke constantly when he was 8 months old. We tried EVERYTHING and I mean everything, all the "gentler" methods, like gradual retreat, PUPD etc etc. We persevered but nothing worked and we were at the end of our tether with sleep deprivation.
At our wits end, we tried CC. The first night he cried for 45 minutes, the 2nd for 30 minutes and the 3rd night he didn't wake at all. We were amazed by the results and I wouldn't hesitate to do it again with baby no.2 (due in August) when the time comes and nothing else works.
DS is a very happy little boy. He is not traumatised by this experience. It was 2 nights out of his little life and he doesn't love us any less nor does he think we won't go to him if he's upset. Of course he will never ever remember this but what I do know is that we were ALL happier from that point onwards for having more sleep. I personally believe I did him a favour - he was crying because he was tired and just wanted to go back to sleep but couldn't. It taught him to go back to sleep by himself.
It isn't easy and it doesn't feel right instinctively but if you want results and a happier family all round, it might be worth giving it some thought. I have a friend with a DD the same age as my DS who has woken up constantly since she was a baby and there seems to be no end to it. My friend won't do CC though (her prerogative) but I know it would work.
Lots of people will probably shoot me down and say it traumatises the baby but believe me, we have experienced no side effects at all and we have a confident, independent, happy little toddler who sleeps well at night.