The best out there!
I don't give many pieces of gear a 5 unless they are perfect, and this pack is. The one thing I love about these packs is that they are custom fit to your body. I am a large harness, large pack, but small or medium hip belt. Other packs I have looked at won't fit my hips correctly. This pack is rated up to 80 pounds, but you can carry more.
This pack is so great that even with 75 pounds on my back I still can hardly feel it... not many packs can do that. It hugs the body really well and has a ton of cool features to go along with it. It is made of heavy duty material which adds a little weight, but extends the life of your pack.