I'm an AT hiker but I hate the short-shorts. I prefer the length to be just above the knee. If you've ever walked through a tall patch of poison ivy before you noticed what it was, you'll understand.
I’m in the shortest-shorts camp too. Less about the UL-value of the shorts, more about the mobility to lift my leg as high as I can (specifically to reduce friction going uphill). When you take literally millions of steps on a thru-hike, even the smallest things start to add up.
