I am in field service, so a lot and use the charger on a regular basis to charge my iPhone, and now and then for the external navigation device. The charging current is indeed stated with 2.1A, a complete charging of iPhones but takes just as long as with the 230V plug from Apple, although this only outputs 1A. I suspect, therefore, that per USB socket "only" about 1A is available and the 2 Ampere can not be used by a machine alone! (For comparison, a USB port on the PC or laptop is often only 500mA available)
However, the so-called LED charging indicator is not really a charging indicator, the blue LED is always on, even without customers and even when the battery is fully charged. Depending on the location of the cigarette lighter, the glaring blue LED may interfere in the dark, but this can be easily addressed (either taping or black Edding to help take).
Overall, a very useful tool in everyday Chargers madness and thus a perfect score. I do not want to miss the part!