I bought this to act as a receiver, so that I can play spotify from my bluetooth phone (HTC One), on my speaker system.
I wanted a wireless setup so that I could hide all of the cables. I wasn't interested in the fact that it contains a battery, as especially for receiver mode, the device it connects to will usually be mains powered. I wanted to power it from the USB port on a TV, or from a USB mains charger.
This device has two unbelievable design flaw however: 1. It switches off after 10 minutes when no device is connected, even if it's on mains power. You must push the button on it before you can connect to it every time. 2. The receiver does not switch on automatically when mains power is connected.
It's fairly disappointing that these issues mean it's not possible to hide this device behind a cupboard or behind a TV/stereo system, or hide it inside the wall. I have to fish it out every time I want to use it just to press that button.
Also you might think that you could power this device from the USB port on the back of a TV or stereo system, such that it will switch on when you switch on the TV/stereo. But issue 2 means you'll have to fish it out from behind the TV every time.
On the plus side, the sound quality is very good, it works well with my HTC One phone which has aptx. But on a day to day basis, using this device is just frustrating, and due to seemingly obvious oversights in its design.