I have a Jam2, the earlier version w/o the hip belt pockets. I use it almost exclusively for hikes of up to five days.

I have used it a couple of times with all my gear and a Bear Vault 500. It worked but it was a little more than the pack seemed designed to handle in terms of volume; it is fine with the BV-200 "weekender". I generally get about 15 lb (10 days) of food in the BV-500 and the jam is OK with the 17.5 lb food and canister weight

I performed some surgery on the Jam and got the weight down to 18.5 oz. It is durable and comfortable to carry.

I just finished making a G-4 pack for longer trips where I will need to carry the larger bear can. Still working on the best way to load that pack but it is also comfortable.