The Salomon S/Lab X-Alp Alpine Touring Ski Boots are a further development of the well-regarded Arc'teryx Procline series, which was developed jointly with Salomon in its Annecy lab. While the Procline is designed first as a winter alpinist's boot, the X-Alp takes the concept more in a ski touring direction. Salomon has added a ribbed exoskeleton similar to that of the Lab/Explore boots to the midfoot area to stiffen the shell under heavy load and give the boot more skiing power. They've also forgone the fully zippered gaiter and cable pressure distribution system on the lower buckle and used lower density rubber in the sole with no rubber cover on the toe. In the meantime, the X-Alp retains the best-in-class range of cuff motion and the only design that offers lateral flexibility at the cuff in tour mode. The X-Alp is still a niche boot designed for long days and big vertical, but now it's one that skis better.