This is really 4.5 stars.
I've had this rocker for about a week and can safely say it's great. My 3 month old loves it, and that's about as good as it gets. If you buy it and find out your little one loves it, definitely worth it to keep.
For starters, the thing is small, like really small. The profile can fit into a corner of a room, with no problems. One of the smallest seats you can find. Unpacking and setup is also a breeze, so no crimes there.
The chair has 5 modes that mimic different motions, and all work pretty well, along with 5 speeds to pair with them. There are also 4 sound profiles to use, although all were sort of average on what they give you. There is an audio in MP3 jack to plug in your own tunes for the baby. The whole seat is controlled by an AC adapter, so that's also a plus (with the cord being decently long.) The seat is also adjustable to fit most infants/babies, and supports 25 lbs.
The seat also features Bluetooth capability via a 4moms app, but this is where my one bigger con comes into play: in order to use any of the Bluetooth functionality, one has to create an account in the app. This is a small issue, but I find it sort of odd that it's necessary to do. Also, like I mentioned before, the sounds are pretty dull. Heartbeat never really helped sooth my child, and Ocean was the only one that really sounded good and calming. When the volume is turned up the speakers are pretty muffled, while the sound was distorted. Price is a little high, but just like any "in" baby item, you're paying for the brand, quality, and form factor here.
Aside from those issues though (the sound isn't a huge one to me, as it works and not sure what I was expecting), the seat really is well-designed and executed, provided your baby likes it. Not all will, but I would recommend trying it out just to see. Bluetooth never lost connection, and controls are easy to use. Never encountered any issues with the playback or motion of the seat either. So all in all, a great little infant chair.