I typically fly to Europe for a month or even more and then within Europe I fly back and forth. It needs to pull dual duty: in hand personal item containing all the electronics for transatlantic trips so organization, yes. Lightweight matters less because it's small enough that not a lot can be packed inside anyways. And then backpack for my short trips within Europe so it needs to be able to house a little clothing as well.
It is the large backpack that needs little organization and wants to be lightweight (if I need organization I can add packing cubes). My choice of bag is the Eagle Creek Cargo Hauler. I learned this split (clothes on the back, electronics in hand) from the Tom Bihn website talking about their Aeronaut bag.