The Wiesshorn GTX will be a little warmer than the Vertical GTX. the Weishorn has an adjustable double tongue and uses Gore Duratherm insulation which is located behind the Gore-Tex liner which insures your insulation stays dry. the split-grain mountaineering leather and high rubber rand on the Weisshorn help to retain heat better than the Synthetic upper on the Vertical. the Vertical is excellent for mixed climbing and vertical ice because it is so light, and has a completely rigid sole. The Weisshorn is excellent for vertical ice and general mountaineering.