I saw a few negative reviews and they could just be isolated personal experiences with bluetooth or faulty units. I was seeking a solution to use with my CarPC project that handles both A2DP and HFP using one device rather than rigging a solution that involves multiple devices and hookups. I can pair my phone and listen to music through it allowing the music to flow through my car speakers, in addition to making and receiving phone calls. Awesome! All from one device.So there is one drawback that makes me want to look for different solution in my car. While you can pair multiple devices only one will connect at a time. So you can listen to music through your tablet then expect to make calls from your paired phone because only one device will connect at a time...but that's it. Not everyone is using this device as I am so the simple solution out the box works as described perfectly.oh... and yes it does take too long for the device to power up after the car turns on. That is my other negative point.