Generally I head out for 3-5 days with a couple of buddy's. I rarely hunt for that long but we do a lot of camping. This past summer we decided that we needed to get further in than our fat butts could carry us so I decided to build my rig. The nice thing about this pack is that it breaks down into 3 separate smaller bags. Plus I have the tactical weapons carrier which makes it very easy to carry just about any style of hunting/tactical weapon you can get your hands on.
http://www.youtube.com/watch?v=-8bU7vcvadMI like it because I can pack everything I need for 5 days and just throw it in the truck. Then when we want to get out I will be able to break it down to something more manageable. I also have the G4 Operator pack from them but it was just to much when I would only be out for a short time.
Then there is the "bugout" scenario. I have handed my other pack down to my son, so between the 2 bags we have enough space to pack for 3 days of contingency for the entire family.