Granite Gear's Vapor Ki isn't the lightest of the lightweights for the UltraLight walker, but it is a long way from heavy. It is by far the most comfortable pack I've worn, and now that I have well over a 1000 miles on mine, I can attest to its durability. I bought Vapor Ki for my wife and she loves it; when mine wears out I look to Granite Gear for my next pack.