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 16 inch Laptop Backpack - Black/Gray
Amazon.com: Wenger Ibex Laptop Backpack, Fits 17 Inch Laptop, Men's and Women's, Black/Grey/Blue : Clothing, Shoes & Jewelry