I have the Detours Sienna 30 liter. It has a curved insert to keep your back ventilated, but the insert reduces the true capacity (volume). It has a detachable helmet harness which I find quite ineffecient. It's easier to just clip my helmet to the handle. I also took it hiking in a Sierra Thunderstorm and discovered that the stowable rain cover can become saturated and will allow water to penetrate. Other than that, I like the fit and the stitching seems sturdy. I just need to Scotch-guard the rain cover.