I just looked at both and you've got a tough decision ahead of you ~ both are beautiful and very different. I think the style and color of the Kooba will take you beyond fall with its classic lines and understated beauty. It's elegant and sophisticated. The Leyla is great also ~ it exudes "fun" with its contrasting beige topstitching, although this strikes me as a much more casual bag. It ultimately depends on what you want from your bag.
Are you concerned about color and/or style trends? Which color is more versatile for your wardrobe?
To me, the Kooba whispers "I'm here, take notice". In contrast, the Leyla sings "hey, check me out!" Just my $.02 at this wee hour in the morning, lol!
Good luck deciding!