We have it and we loved it, many long nights were saved by it. With that said, it's just like a swing or a bouncer where it's hit or miss depending on your baby.
It's as "must have" as a swing or a bouncer, and like pp mentioned, the newer models move a little faster than the older ones (I have the 2010 model I think). Anyway, it worked really well for us, and we used it for a long time with our 1st, she didn't grow out of it quickly or anything. When she started daycare at 3 months, we found she always really likes a swing. Good luck :)