Bought in May 2010 on Amazon for 120 euros and almost exactly 2 years later I also had the smoking engine. And I took the wrench only every 6 months, to times to hang a picture on a piece of furniture or to screw together. Based on the mileage I have to say: Not even worth 1 star. The accessory is quite useful if you only do small things. For permanent use, however, I would buy a set of higher-quality bits and drill it.
Since it already was now the 3rd unit of Bosch, which is fitted smokes me after 24-30 months, I will look for another manufacturer.