Arc'teryx Mantis 26 Daypack - 1587cu in

The stiff plastic back support is light and works well with the mesh/foam back padding. Nice sized main compartment with three other good storage compartments. The smaller compartment has useful pockets for pens and calculator, and a clip for keys. The side pockets hold small to medium water bottles securely.

I use this pack for school and I love it. As with all Arcteryx products, there was a lot of thought put in to making this bag. The front pockets are great, they are essentially the same pocket, with fabric dividing them on the inside. In case you need to fully utilize both pockets as one, just fill the right side and the divider expands giving you access to both pockets as one.
The main compartment is well suited to handle quite a few textbooks/binders, and the frame curves with your back so the books are note felt against your back. Depending on your laptop it can be a VERY tight fit, since I do not use one (simply tested it with my fiance's) I do not have to worry about this. Overall though the storage is more than you expect by looking at the bag.
The top pocket works very well for bits and bobs, and makes a lot more sense than having a front pocket like normal book bags. I can just reach down in class and it's already almost at waist level. The padding and the frame make for a comfortable walk around campus, as the aesthetics make for stylish walk around campus.

The only downside, which really bothers me, is that the side pockets do not comfortably fit a 32 oz. Nalgene... You CAN make it fit but it doesn't even make sense, you are over stretching the panels, probably seriously jeopardizing the elasticity of the pocket, and it does NOT slide in and out, it takes both hands and some pull to get it shoved down in, so no on the fly grab, drink, and re-insert. It requires you taking off the pack to put it in, I bought a Camelbak Podium water bottle to solve this problem, and I love the bottle, I just don't know why Arc'teryx didn't consider this.

I can't tell you how much I love this pack. I use it for school, hiking and biking and it has never let me down. My friends call it alladins lamp because it holds so much that just seems to disappear. Highly recommended.

If you are looking for an ordinary daypack, I m sure Arc'teryx Mantis will be perfect. BUT its is not designed to fit laptops. For its so called laptop pocket is arc shape, rather than flat. I seriously doubt what would happen if you really put a laptop in it.

The main compartment fits a 1.5 inch 3-ring binder, a 14" laptop and a medium sized textbook. A 15" would probably fit fine as well. The side pockets fit a tall 1L bottle but it's tight, so I'm not sure about one of the shorter/wider 1L bottles. The top compartment has plenty of room for a calculator, pens/pencils, and all the small stuff. The two front areas are roomy and good for some gym clothes or other things that aren't too rigid. The waist strap doesn't do much, but this pack isn't big enough to warrant them anyway. The shoulder straps are a bit stiff but it's still new so i'm sure they'll break in over time. Overall, this is a great, balanced pack for school as long as you don't need to bring more than a few books. I bought is because of the load balancing which is focused more towards the top of the pack and whether walking or biking, this pack does just fine.