I have a question about ultralight packs that use the z-rest or similar pad against your back for the pack's structural support.
I have an old Jannd Zoor Alpinist and I'm thinking of modifying it. I think I could save a little weight and cut the padding out of the back of the pack and instead just lash my z-rest to the back.
How does that feel to have the foam against your back? Does it get uncomfortably sweaty? Not any worse than anything else?

