I used the hammock with my baby because of GERD and it was a miracle. Before that, I had been rocking, swinging, marching him around to get him to sleep and then he wouldn't sleep for more than 20 minutes at naps. This hammock saved my life, literally. Before it I could not put him down awake, he would cry for an hour and not go to sleep even with PU/PD method. The first time I used it, I put him down in it awake and he fell asleep on his own within 10 minutes!!!! I used for a month and he began sleeping through the night.
Then as he got older, he began rolling over on his tummy, which the bed is not made for. So reluctantly, I transitioned him to a crib. I was really scared that because the crib had not bouncing motion, that it would be hard. But I put him down awake and he fell asleep on his own just like in the hammock.
So for me, it was an absolute life-saver and helped me with getting him to sleep independently. It was well worth the money, even for 1 month. As soon as he started using it, he stopped crying as much and would wake up happy.
I cannot say enough good about it. But that's just my experience.