We've lugged around an Oakley Kitchen Sink backpack for the last few years. It has proven to be a handy companion, but it is a pretty heavy backpack with few technical features. This is one of the reasons why we started looking at technical backpacks for our next daily pack. Technical backpacks distribute the weight of books, laptops, and gear a lot better than regular backpacks using an internal frame which relieves pressure/tension, the very same solutions relied upon by hikers and backcountry campers to traverse vast distances with heavy loads on their backs.
We ended up choosing the Gregory Z55 for our specific needs (which included weekend hikes). It was between this model and the Deuter Futura Vario 50+10L. The overall construction of the Gregory and the fact that it compressed down to something quite svelte sealed the deal.
What to look for in a technical backpack
1. Laptop sleeve, pocket, inside the main compartment of your pack: Having one with side access is nice, but not always necessary. Most technical backpacks don't have these, but almost all of them have a large hydration sleeve on the rear panel, which can easily double as a laptop pocket if you leave your laptop inside a dedicated sleeve already (say one from Incase).
2. Lots of pockets: You'll need plenty of pockets to store all of your gear, from smartphones, tablets, to books. Make sure that your next backpack has enough pockets. A lot of technical packs have hidden pockets, which are perfect to stash your valuables.
4. Correctly fitted & appropriate size: A lot of packs come in different sizes, S, M, and L. Make sure you get the right one. We initially thought that a 25L pack would work for us, but after trying out a few different packs, it was apparent that we needed something bigger. 55L might seem a bit much, but it will be able to carry all of our library books and class books. With our previous pack, we actually needed an extra shoulder bag to haul all of our books to the science library the last time. It was somewhat tedious (especially on a motorcycle).
5. Sturdy straps: Take a look at the shoulder and waist straps to make sure that they can take the load that you'll end up carrying. You don't want them to give way.
6. Significantly curved rear panel: Usually technical backpacks have some kind of curve so that they can cling to your back better. If you decide to buy a technical backpack, make sure that this curve is not too pronounced. We have two Osprey Atmos packs (25L and 35L) and neither is suited for lugging around books and laptops, mainly because of the slope of the curve of the rear panel.
7. Waterproofing: While this might seem a good idea, it's usually overkill for a daily pack. Weather-resistant packs have also less or no pockets, making them less usable as a daily pack. They can get very expensive, $350 to 500.
8. Urban or city backpacks: If you're looking for something different, you should most definitely stay away from urban backpacks, as they won't distribute weight on your back, and leave you hauling their complete weight with your shoulders. A nice, thick waist strap will make it a lot easier to carry around heavy loads.
9. New models: If you're trying to save money, try looking at models from a year or two ago. Most outdoors shops will have them on sale, saving you between 10% to 30%.
10. Pushy salespeople: It doesn't matter if you're on a budget or if you've got money to burn, if a pushy salesperson gets to you, its best to just go to another store, or even better, buy your backpack online. If you do end up buying it online, you'll probably find it cheaper.