I started using it with DD3 fairly early on. I would give her a dream feed around 10pm, but it was more so that I could go to bed knowing I'd get at least a couple of hours before having to wake for another feeding session. She was until very recently a shocking sleeper, so that initial block of sleep was the best I'd get all night. It certainly didn't work for prolonging her sleep or helping her sleep through the night - purely for my benefit.

Neither DDs 1 or 2 had dream feeds. I tried a few times with each but they either flat out refused the feed, or they woke for it and then were cranky and took ages to settle. Worth giving it a try, but also be prepared for it not to work. Like MadB said, they all come with a different set of rules so don't feel like you're doing something wrong if your LO doesn't take to it.