I bought this for my school bag but also to use when I fly with my laptop. For school it's wonderful. I have never run out of room with this. Textbooks, binders, lunch, whatever. I always seem to find more room... I gave it 4 vs. 5 stars for the same reason as Jason - the front pouch's zippers do not go down all the way so it makes the organizers essentially useless. i.e. I can never actually get a pen into the pen slots, I just push them randomly into a pouch. Otherwise it's a 3 minute process to straighten out the bag enough to expose the pen slots. Minor inconvenience, but why even have them if they're so difficult to get to?
Regardless, I love the bag. The airmesh gives good ventilation down my back and the straps are very comfortable. Very versatile bag.