camdancer and cerealqueen, we did CC with DS (7 and a half months) recently - a mild version with shorter increments of time (more like Jo Tantum's 'spaced soothing'):
We settled him, made sure all was well, then left him for 1 minute (in for c. 30 seconds to check - to stroke his head/replace dummy/reassure him/repeat sleep cue phrase), 2 minutes, check, 3, check, 4, check, then 5, check, and repeated 5 mins thereafter, if necessary.
The longest he was crying (with us going in and out at the specified intervals) was 35 minutes. It was hard, very hard, but he's cried for far longer than that at times when I was feeding him to sleep and trying to resettle him in his cot. We co-slept for ages too but it had just become so uncomfortable for me, I was in pain every day.
We decided to try it once he was over 7 months, having three meals a day plus plenty of breast milk, used to his cot, and used to playing lots and lots of 'peepo!'
So, the first night he woke three times, and it took 35 mins, then 25, then 15. The second night he woke twice, and was settled back to sleep within four minutes. Now he might wake a few times but go back to sleep within a minute - or sleep through the night without a peep!!! This is a baby who would wake up every 60/90 minutes through the night, and used to feed loads, just to get back to sleep.
It has been brilliant, and DS has been happier and more alert ever since (as have we!). His relationship with us hasn't been affected adversely in any way and he is as friendly, smiley and intrepid as ever. And bedtime has become a pleasure - I can read him a story while he smiles at me adorably, sing him a song and leave the room with him relaxed and happy
He isn't scared of going to sleep any more.
By the way, when he was teething, I knew immediately that his cry was different (more acute, higher pitched, sharper, louder) to his annoyed shouty "Oi! Mother! Here, now!" cry, so I went to him straight away, gave him medicine, rubbed stuff on his gums, cuddled him etc.
Disclaimer: I know this won't be right for everyone, and some babies won't respond so well. We didn't undertake it lightly DH had to deal with DS and me crying at the same time but I really feel like DS has learnt a skill and it has made him more confident and definitely more rested. In fact he started proper crawling two days later but that could just be a coincidence.
I just wanted to put this out there, because I was SO exhausted and ragged and tearful and edgy, so miserable with fatigue (still have a big sleep debt really but we're working on it!). And I couldn't see how that would ever change: the thought of any kind of CC made me feel horrendously guilty.
But I feel like we made the right decision. Hope this helps.