Here are a few size comparisons for the different Gura Gear camera backpacks - I wish I saw this before I got a too-small Kiboko backpack.
Gura Gear Kiboko 2.0 camera backpack size comparisons:
Gura Gear Kiboko City Commuter 18L+ camera backpack size comparisons:
New: Gura Gear Kiboko 30L+ camera bag now with a laptop sleeve (10% off code included)