I laid out the inside picket for an older Lenovo laptop. I can now fit two smaller surface books in that pocket! I can also slide a surface book in the magazine pocket on the back for quicker access.
Infront of the laptop sleeve there is actually a good amount of space. I can fit my charger, adapters and connectors at the bottom of the front along with my small umbrella.
I leave my cell charger and cables in one of the front buckle pockets on the front of the bag for quick access.