It did help us with teaching independant sleep at one stage - changed what had been a 2+ hr fight with beyond hysterical screaming to get her to sleep into a 40 min one. Didn't take the problem away, still had to sleep train, but made the training manageable iykwim.
Might be worth noting here, that for us, it was not a permanent solution. Some kids just need their parents at night, at my DD is now kind of co-sleeping. she usually falls asleep on her own in our bed, we move her to her own bed she returns int he night - now we have a matress beside our bed, so she usually sleeps there, but is welcome to go to her own bed whenever she wants (and sometimes she does). we are all sleeping much better.
DS still sleeps in his own room - he doesn't need us anywhere near like DD has always needed us.
