My "main" pack, or the one I find most comfortable, is a BD Shadow, that is rated at 55L, or 3356 Ci. I have heard that this pack is kind of lousy at it's upper weight limit, but I have usually kept it at 25 pounds or less and it has done great for me. I also have a couple other packs for vehicular hikes, and I must admit the Gregory handles more weight better, but it just doesn't "feel" as good as the BD.