The X Pro 100's progressive flex will be highly welcomed by the lighter weight advanced skier or someone looking for a more forgiving comfortable boot. The 360Adeg Custom Shell's heat moldability allows the boot to have a 100mm to 106mm last. The shell is paired with the My Custom Fit 3D Performance Liner that is also heat moldable to give a truly custom fit right out of the box. Salomon uses their TwinFrame Technology to stiffen the boot where needed and combines this approach with softer materials in areas that affect comfort. Many ski boots fail to transfer energy from the cuff to the lower part of the boot, making it difficult to keep a ski on edge. In order to combat this issue, the X Pro 100 has a 24mm oversized pivot to aid in power transfer. If you plan on doing a lot of hiking you don't have to worry about wearing out the soles because both the heel and toe sole blocks are replaceable. This 4 buckle boot is a good option for those skiers looking to advance their skill level or for the lightweight skier who wants to push her limits.