... Though we were skeptical at first due to the shoes’ thick and sturdy appearance, their climbing ability left us immediately impressed. We tested these shoes on the coastal sport climbs of Northern California, and they managed to handle tiny water-polished footholds with ease.
Because the Merlins are super-stiff, they are the perfect shoe for technical edging on vertical to semi-steep terrain. Even when applying lots of weight and power to the toe edge of these shoes, the arch of the foot is supported, and the heel hardly sags. The plentiful support also keeps the feet from becoming pumped and tired.
...The Aztecs are comfortable straight away, and they continue to break in and stretch during their first few sessions of use. Though these can be sized aggressively, we found having a bit of extra room in the toe can actually be an asset, especially when climbing thin cracks.
Though these shoes work best for crack climbing and vertical to slightly overhanging trad climbing, we found they work quite well for steeper terrain too. Even bouldering felt natural in these, especially on problems that required smearing or stemming.
While climbing thin cracks, we were impressed with how well the toe point of the Aztec pinches down and inserts into narrow fissures. Compared to other popular trad climbing shoes, the Aztec performs exceptionally well on offset cracks, laybacks, and flaring seams.
The Aztec has a nearly flat last with just the slightest downturn, and Acopa’s RS rubber feels especially sticky on these shoes. When jamming in flaring cracks or pinched-off corners, the rubber that lines the outside of the entire shoe adds lots of friction and inspires extra confidence during delicate movements.