I have been buying the Scosche reVolt 2 dual car chargers. Rated at 12 watts per port, very compact. They work well but seem to cost more than the Anker equivalent.

The only reason I have not switched to Anker was a few online reports that sometimes the Anker car charger would not properly charge an iDevice unless the USB cord was removed and reconnected. I really want the full 2.4 Amp charging to work reliably with my iPhone and iPad.

There is a lot of internal dancing around these days where the 'USB' charger tries to be compatible with everything and every charging 'standard'. I didn't want any weirdness with the in-car USB chargers so I am still buying reVolt 2 chargers.

Next time around I may try the Anker product