My online retailer of Victorinox and Wenger is awesome! I asked him for the difference between their Ibex, Synergy, and Pegasus backpacks, and he sent me this photo and called to explain.
Wenger Synergy Wheeled Backpack for 16" Laptop (Black/Gray)
Brand New Wenger Synergy Pro Backpack for Sale in Seattle, WA - OfferUp
Wenger Synergy 16 inch Laptop Backpack - Black/Gray
Wenger Synergy Ballistic Laptop Backpack Black - Office Depot