I have difficulty finding the kind of backpack I ideally want, with two main pockets to keep a laptop separate from a notebook and perhaps a book to read, and a mini-pocketed-third-pocket for miscellaneous little things I like to keep with me (checkbooks, pens, change, stamps, tape, passport when travelling, sunglasses), elasticked pockets on the side for stuffing a can of coke or a leftover half-burrito in, and a pocket on the front for maybe some kleenex or spare napkins or hat.
The one I got meets the specs except for the two-main-compartments bit. Since I tend to have fewer books on my person than I used to in my past academic life, I guess that's okay. My previous backpack did have all the pockets I wanted, so I used it a long time before finally giving up on it. I wore it down really hard; holes in the arm straps, and bits of weird plastic fabric stuff kept flaking off the bottom. It had really good padding around the shoulder straps and the little hand strap, and good solid, big zippers. Gonna miss it.