I've had this piece of kit for just over a week now and, I have to say, it does exactly what it says on the box. No problems with set-up and only a brief read of the (simple) manual allowed all facilities to be used. Intercom, voice dial, 3-way conference all work fine and people I talk to on the 'phone tell me that all they can hear is my voice, with ambient noise effectively cancelled. The auto-volume adjustment also seems to work well in all conditions I have tried so far.
However..... there are a few drawbacks! I ride three types of motorcycle; a moped (for to and from work), a big trailie and a Harley. I also have a Garmin ZUMO GPS which I have used on all three bikes with both a wired connection and now the bluetooth connection of the Scala. With the wired connection of a really cheap intercom system (£4.99 from Lidl), the audio quality for 'phone and MP3 and are pretty good, with workable but noisy intercom. In comparison, the Scala is OK on 'phone and intercom, but apalling on MP3 and voice directions from the GPS. The speakers are very tinny with no bass and no depth; MP3 is a joke and voice directions are completely drowned out by the tinny whine of the moped, the wind noise on the trailie and the deep rumble of the Harley. Fitting better speakers might be a solution but I don't know what this would do to the battery life and there is no 12V charging facility so, when touring or camping, battery life may become an issue.
A good set-up for communication but, if you want MP3 and voice guidance for cruising, long trips and those relaxed rides, look elsewhere.