For the trip to the west coast I took the Gossamer Gear Gorilla. The total volume of the pack according to Gossamers Gears website is 46 litres with 39 litres in the main bag section, which seem about right to me. The pack therefore is a good size for trips up to 4 or 5 days, depending on the volume of your gear.
The pack comes with bungy and cord locks as well as foam inserts for the hipbelt and the shoulder straps and the Sitlight pad which has its own sleeve on the outside of the pack. I inserted all the foam inserts in their respective places but felt that the shoulder inserts tended to push the shoulder straps into my neck which I found uncomfortable. However, the beauty of these packs is that you can open the shoulder straps and put in socks or hats etc. for padding. So I replaced the inserts with Gossamer Gear 1/4″ foam which worked perfectly providing both a comfortable fit and cushioning where it was needed. The weight of the large pack on my scales was 730 gms which included the Sitlight Pad. The pack has their U shaped frame which is similar to the Haglöfs LIM 45 as described in an earlier post. To the pack I added two Gossamer Gear Hipbelt pockets (20 gms each) and one shoulder pocket (19 gms) giving a total pack weight of 790 gms.
I started the trip with a total weight of gear, food and water in the pack of a little under 10 kgs, but as explained in the trip report late on the first day I loaded up with an extra 2 litres of water taking the carry weight to approximately 12 kgs. With this weight in the pack it was still comfortable for me. The packs hip belt is much softer than some other manufactures belts, but when tightened up it is effective at supporting the load. The frame works well and in my view allows the base of the frame to flex when walking while staying rigid at the top, such flexing aids in the walking and the pack feels like it is hugging your back. The three mesh pockets are functional and stretch easily to accommodate items such as platypus water bottles, bivies, tarps, Caldera caddies etc. The Gorilla is Gossamer Gears heaviest pack partly due to the heavy duty fabric used for the body of the pack and as a result the pack has a feel that it will withstand a fair bit of punishment either on or off trail.
My opinion, it is a comfortable pack capable of carrying 12 to 14 kg with easily accessible side pockets and an efficient roll top closure. The addition of hipbelt pockets and shoulder pockets ensure that all the gear for the day is on the outside of the pack and there is no need to open the main bag. It is a pack I will use often depending on the conditions and the location of the trip.