Also worth a look in this category:
Laptop protection is the baseline
A padded, suspended compartment is the minimum. Anything less and you are carrying an expensive machine in a school bag with better fabric.
Details that earn their place
A luggage pass-through strap for travel, a discreet rear pocket for a passport, and a water bottle pocket that does not stretch the silhouette when empty.
Backpack or briefcase
A backpack distributes weight over both shoulders, which matters past about eight pounds or a long walk. A briefcase looks more formal but costs you your posture on a daily commute. Most offices now accept both.
