Thanks everybody, although it's not all going quite as smoothly the last couple of nights - ds's cold now has an occasional cough attached, so don't know if that is an issue.
So Thursday (Night 5) and Friday (Night 6)nights:
Night 5 - no crying at all, and slept right through until 4.45am when he had a feed. Then went back to sleep (although too noisily for me to do so) until just before 6am, then awake for the day.
Night 6 - cried for 3mins about an hour after his bedtime feed. Then woke at 1am for feed. Then woke again at 4.55am, but not making much noise, so we left him hoping he'd go back to sleep - he didn't. So fed him at 5.40, put him back in cot, but didn't go back to sleep.
So I was a bit disappointed with last night, and not sure whether it means anything, or is just a blip.
dycey your ds sounds very like ours had become, and I know I should be really pleased that ds isn't doing that any more. Just perplexed by this early waking, which I personally find one of the hardest things (pre-dc 8am would be my preferred earliest wake up. Now I have been re-trained to find 6am the earliest acceptable time lol).
DH found Ferber's book really helpful in drawing up our plan - he bought the 2nd edition (2006) via Amazon marketplace. Maybe we're a bit weird, but DH put together a proposal document, which I reviewed, and then we finalised it together. My point is, it was helpful to have it all written down, so we were both clear what was planned before you got started. Meant we didn't have debates as we were trying to do it.
After last night, think we need to review what we do with feeds, as I had thought we had got down to one nightfeed, so was reluctant to feed again, although that is what our plan says. This stuff is hard!