Jansport Revolt

I am in need of a good college backpack holding a laptop and has plenty of space. So I'll walk a lot, it must be comfortable, I have done much research and laptop backpacks are really worth $ 100. I reduced the revolt and JanSport JanSport Air Cure. What is the best? or do you have other suggestions?

Choose the one that is impervious to water. You never think that until it is too late and you find yourself with your laptop, but having to travel 15 minutes on campus in wet snow and winds of 30 mph. Impervious to water is the most important thing!