Easy installation, several cable versions included. Already at 6-7 km / h my Samsung is charged via USB. Deficiency is: the contacts after several months (I drive not only with sun but daily) are somewhat corroded. For 1 point deduction. Another relative lack: as I alternately use two wheels, I'd like to have two sets of cables for mounting on the hub dynamo. The device is very easy to assemble, but the fumbling at the cable connection of the dynamo is not what I want to do every few days.
Both flaws could be affected by a possible replacement of cables. One would however wish better, corrosion-resistant contacts.
Postscript Have Busch & Müller contacted and get unbureaucratic supplied replacement cables. This earned the company full 5 stars!