It was very hard for me to vote, but I voted for the Kooba Scarlett - because I have that exact bag in the cream and I can't even begin to tell you how gorgeous it is in person. The leather feels all buttery and the color is so versatile. I can't rave about it enough. Best bag purchase I've made thus far. That being said, the AB is definitely my next bag purchase.
I love both so it was a hard vote but I voted for the AB bag pretty much because it would go with my outfits better than the kooba. You couldn't go wrong with either bag though.