We have gone through phases with sleep with S but she is a good sleeper.
We co sleep and I have never done any sleep training.
She has just gradually reduced her feeds at night as she has got older. But interestingly I think she dropped the last 2 feeds, middle of the night at 4 and a half months, then she dropped her 10pm ish feed a month ago. I think the timing of this coincided with me getting the start of thyroiditis ( as in based on my symptoms not definite diagnosis). So now with the benefit of hindsight I am pretty sure my milk supply, well let down has been affected, mainly noticeable with late evening and night feeds, so I think she just decided that they weren't worth waking up for! She actually still really needs that last feed though as she was waking up with almost dry nappies, after 12 hours! So I have started waking her for that last feed again. Maybe she just loves her sleep so much she can't be bothered to feed!
I have read though that babies often are frequent night time feeders who have mums who are working full time as it's there opportunity to have some mummy time. I have a good friend who did extended breast feeding and her DD was a great sleeper from 6 months. However her DS who is now 6 months is a dreadful sleeper and waking up 2 hourly. During the day he has to compete with a 3 year old for mummies attention and at night gets her all to himself! But I'm sure you've read all of that with this been your obsession! But out of curiosity does he feed less at night at weekends or when you are around during the day with him?