The Good: The core idea of the 4moms MamaRoo is clever and solidly implemented. Being able to rock your baby to sleep hands-free can offer serious relief to new parents. The Bad: Most of the extra features are disappointingly low quality: the poor speakers, the plain mobile, and the completely useless ambient sounds. The Bottom Line: The MamaRoo is admittedly pricey, and it won't be for every baby or parent. But for a parent that could use an extra set of arms, or any kid who can only sleep while being held, this 4moms device could make all the difference In the weeks before the birth of our first child, my wife and I emptied our bank accounts buying every baby accessory we could imagine using even once or twice. After our son was born, we spent hours repackaging and returning a lot of them, because we found out the kid had his own preferences. He hated the first bassinet we bought for him, but loved the swaddling cloths. He hates to be cold, but he likes baths. And during this process, figuring out which devices to invest in took some experimentation.At $270 (about \u00a3186 or AU$361), the 4moms MamaRoo is an expensive experiment -- especially for new parents being bombarded with medical bills and nighttime diaper runs -- but it's one that could pay off. Essentially, the device is a Bluetooth-connected chair that, according the advertisements, "moves like you do." 4moms attempted to replicate the range of movement patterns and speed that parents use to rock their children to sleep. Whether it calms your child will depend on his or her particular preferences, this base mechanic works really well.The MamaRoo isn't a perfect product. It has major technical shortcomings --particularly with its basic mobile app and terrible speakers. Even in light of these issues, I like the MamaRoo. Unless you've got $270 lying around, though, you should wait to buy it until you're sure it's what your baby needs.What does it do right?The 4moms MamaRoo is basically an adjustable seat that can rock your baby in various patterns at a few speed levels. The seat can sit up for babies getting a handle on balancing, and it can lie back for newborns. The seat itself is made of a soft multi-plush material that is gentle on the skin (though a slightly less expensive model just has a rough nylon material that you'll have to line with your own blanket), and it's machine washable. Setting up the MamaRoo is a breeze. The instructions are clear, the pieces fit together simply, and connecting it to your phone with Bluetooth will take a minute at most. I had my MamaRoo up and running in less than 10 minutes.MamaRoo also features a hanging mobile, speakers, and sound effects to calm the baby. You can control the volume, select the sound effects, adjust the movement speed, and choose the movement pattern, all from an app. It's like you get an extra pair of arms to rock your baby, and it's mostly hands-free for you.My wife parents full-time, I help as much as I can, and our son is surprisingly relaxed. But we still felt the relief of having a device that rocked and engaged him. For fussier kids or busier parents, MamaRoo could be a lifesaver.