I've read several critics about either the no sound or poor sound quality, but even so, decided to try it to use the Bose SoundDock with a new Samsung Galaxy S3 4G.
At the time I bought it there was no seller in the EU or Amazon UK, so I got it at the CableJive site.
The operation is real simple, but some points that one must remember: On the Acessories options on the Samsung (Android 4.1.2) you MUST set the audio out option to the external speakers (otherwise you won't get any sound) and the female 30 pin plug MUST be correctly inserted on the SoundDock, failure to do so will result in poor audio quality as reported due to poor contact of the 30 pins plugs.
As a simple accessory it just does what it claims, and, at least to me, does it correctly and best of all re-enabled an expensive Bose SoundDock.
Some of my friends that had similar problems (either SoundDocks, B&W Zeppelin or even 30 pins plugs in the car) have already bought the same cable with similar good results.
As a plus it charges the phone battery, which on the Galaxy S3 4G is really necessary :)
One minor issue I found is that the usb plug that goes to the phone is perfectly flat on both sides which might be a challenge to plug on the phone in the dark. I solved this by putting a small drop of superglue on one side to the usb plug.
Would buy it again.