Tony bought me a Gossamer Gear G4 backpack for my birthday. He gave it to me as soon as it arrived. I'll be able to use it on our trip over Presidents Day weekend. I'm a little worried about that, though, because our backcountry has snaggy scrub that tends to tear our packs. But our leader for the trip (it's a work trip) insists that it'll be fine.
My z-rest pad is 12 panels long. I like a long pad because I like cushioning under my heels. The backpack uses your sleeping pad as a frame. It provides stretchy fabric to slip the pad in between the pack and your back. But 12 panels is too thick and the pack feels odd pushed so far from my back. Also, it bows outward toward my back and therefore doesn't feel like it is doing anything to provide support for the pack.
So I put the pad inside. I arranged it so that 4 panels lie flat against my back and the other panels form walls on the sides of the pack. This has the benefit of providing rigidity.
I look forward to testing the pack on our trip. It's a rather large pack so I just stick everything inside. Without pockets or a lid on the pack, it seems odd to me to just toss everything into the pack. There are all kinds of little bags of things in there. It's messy and disorganized. But I'll get used to it.
I'm going to try not using a Camelback on this trip, too. Last year on the PCT I usually carried my 2.5 liter Camelback, a 2 quart bottle and possibly another liter. It was more than I ever needed and awfully heavy.
My plan this time is to fill up two 1-liter Platypus bottles and carry a 20 oz bottle for drinking and making lemonade. Whenever I arrive at a water source, I will drink deeply to make up for carrying less. Where water is plentiful I won't even have to fill all of that up. I may also carry an empty 2 quart bottle for those really long waterless stretches and the ability to walk on after dinner to a dry campsite.