I offer this as a frequent CO visitor as opposed to a local. It really depends upon what is important to the two of you. Make a list of what matters most to you and see how each locale measures up. Durango has quite a bit more public land immediately surrounding it. It's a larger town with better medical care options. I can't really quantify it, but Durango has a better vibe to me. More of an old western feel than a hippie feel. Salida wins on access to the major metropolitan areas and the airports. The climates are similar.
