I'm a big fan of ULA packs. These are essentially sold only online, so the company is easy to work with, i.e., don't buy something custom and they have a good return policy if you just don't like it. Generally I find that if I send them an email query, Chris there answers it the same day, and I once ordered a pack from them while I was on a hike and they mailed it to a trail town. You can also call them and just talk things out. You measure your torso length and waist size and at least for folks I know the pack comes out the right size.

To be clear, I have no relationship with ULA, though I might sound like a shill ... :-) I've got a total of 3 of their packs, and am close to replacing one of those with the same model. This one (a "circuit") has about 7000 miles on it, and still works fine overall, just showing some minor wear here and there so that I'll be more confident on longer trips in future with a new pack.

So from that I can say that the durability is very good, yet these packs are pretty light and have IMO the right mix of features and ... lack of features (to keep weight down). You might or might not agree, but among long distance backpackers ULA is a pretty popular choice, FWIW.

http://www.ula-equipment.com/

Gads, maybe I should ask them for a commission ... seriously, I just like their products.

One caution on lighter weight packs: when you compare the size/volume of different packs, have a care about *where* the volume comes from. Some packs get all or virtually all of the volume from the main pack body, but for lighter packs the total volume listed often includes a lot of volume of things stored in external mesh, with the actual main pack body being a subset of that. Fine so long as you know what's going on. The better companies (ULA included) break these numbers out when listing the specs.