I've browsed it at the library. A co-worker of mine said it worked great with her son. When I read it I was intrigued by the sleep info BUT upset that he completely and totally advocates CIO. He says to lie your baby down at the set nap times you determine and let them cry for up to an hour. If they don't sleep he says to take them out and continue your day and then repeat at the second nap time. Says they will learn to nap at those times. For bedtime he says there is no length of time to worry about as far as the crying is concerned. As long as they are not sick, wet/poopy, etc. he says to leave them and they will learn to go to bed.
He did mention other possibilities being out there and was more worried about getting your kids to sleep and wasn't as concerned with HOW you did it. But he claimed there was no point and that they all took too long and that there wasn't a problem with them crying.
So I didn't like the book...but understood and agreed with the importance of sleep.
I think some other moms have read other methods and liked that b/c it used set nap times but then used BWer methods to get there. So not sure if you can use his method for timing naps and apply BWer methods and be more gradual and comforting about it.
Oh, he also advocated a REALLY early bedtime to compensate for any lack of sleep and an early bedtime in general.
HTH.