We carefully considered every model in this review after considering every possible option available in North America. From more technical models that blur the lines of what could be used for even water ice climbing to Ultralite models for alpine rock, ski-mountaineering or spring backpacking trips on the PCT. We bounced every possible selection off OutdoorGearLab staff, our friends and over a dozen guides who specialize in alpine guiding and mountaineering.
We made dozens of trips to test every model in their review both on their own and side-by-side in each category. On one trip, lead tester Ian self-arrested over 60 times, and on another, we moved a nearly car-sized volume of snow digging and comparing adzes. As an IFMGA/UIAGM guide based in Washington's North Cascades Ian teaches people to self-arrest and dig snow anchors essentially every week of the summer, and says: "I have had a lot of time to sit and compare my own uses while viewing hundreds of experiences."
Steep Ice and Snow Climbing
We compared how each model performed while climbing steep snow as well as moderately angled glacier and water ice. We weighed each model's performance in low and mid-dagger positions while ascending thousands of feet of firm snow comparing how effectively and how much energy was required to drive the pick into the snow while gripping the axe on the top of the head as well as under the shaft in mid dagger position. We specifically took multiple axes up classic steep snow routes like The North Face of Mt. Shuksan, The North Ridge of Mt. Baker, and the North Ridge of Forbidden peak to name a few. We also compared each model's ability to climb steeper, firm ice mostly on glacier ice but in a handful of instances, water ice up to WI5 though these aren't really designed for this.
We tested each model dozens and dozens of times. This was primarily done during two huge side-by-side testing sessions where each model was self-arrested with over seven times each. We also intentionally took different axes to compare while teaching self-arrest and took into account hundreds of people's experiences learning to self-arrest with a variety of models.
Digging & Step Chopping
Besides using each model in the real world we literally tested all the models we had in a closed ski resort moving more than a small-bused-sized pile of snow out of the ground while testing each model. We compared each models performance in moderately soft spring snow as well as mid-summer neve. We made sure to document how well each model was able to "break into" firmer snow as well as move it, particularly as when it came to digging "T" trench style anchors and chopping steps.
Use As Improvised Snow Anchor
We tested each model in our review's performance as both a deadman in a T-trench style anchor as well as how easily it was to be placed vertically as a climber might do to back up an existing anchor. We weighted models with easier to clip higher than models that were difficult or very challenging to clip.
Comfort to Carry
We spent literally hundreds of hours carrying each model in our review. We tried our best to balance the time we carried each model in both self-arrest position as well as self-belay position and split comfort in each positon equally to create this category overall score. We wore the same pair of lighter-weight gloves for the entirety of the test to minimize variables and tried to get input from a wide range of user hand-sizes to make sure that a given model's performance reflected all-sizes of people as long as it was appropriate.