The Metolius Alpine Aider is surprisingly comfortable considering how light and non-bulky it is. The Biothane step-stiffeners keep your feet relative comfortable despite the thin (0.80") webbing. The aider is not bulky so it feels nice when clipped on the side of your harness. Most of all, it is a great value considering how high it scored compared to other light aiders.
This is a great lightweight aider that excels in the alpine environment or on mostly free big walls (such as The Nose or Half Dome). It is only a little lighter than the Petzl Wall Step Etrier but is less bulky for free climbing and better for top-stepping. In most cases we would still reach for the WallStep because it is so comfortable to stand in. But if you are on a budget this is the best skinny aider for the money.