The 99.95 and 79.95 dollar backpacks from Incase..which one should I get? I need a backpack that can hold my books for school as well as an iPad, MBP, charger, accessories. I want an all around backpack I can also take to airports, etc. The 99.95 backpack...it says it fits up to the 17inch MBP...does this mean my 13" will fit in the pocket kind of loose? I want a snug fit.