Interesting thread. Imo, the most important aspect of a knife you want and carry all the time, use for any situation a in which you need an edge, is the comfort and quality. You can carry a large knife that is unbreakable, made from a super steel that never needs resharpened, etc, but if its uncomfortable to use or creates a lot of hot spots on your hand, how often, or will you even want to use it? Then you look at quality. Is it custom or large production? What's the makers reputation? How ergonomic are their knife designs? Thats the most important aspect about any knife. I really like Schrade and Tops knives. Not all Schrades are good but they do have some that are just awesome and work great for many tasks. Same with Tops. I like to carry a large knife when ever I backpack or camp along with my Coast folding knife. My large knife is a Tops Condor Alert. 9" blade and weighs in a 26 ounces. It chops and batons very well, comfy in my hand and holds a shaving sharp edge for a long time. I have even field dressed a deer with it and it worked better than my short 4" Tops Intercepter. Why? Well for one I didn't have to get my hand inside the chest or body when removing the organs, I just cut whatever was holding themnin place and used the knife to scoop them out, therefore my hands didn't get nearly as cold or bloody. It worked great to chop through bone like the neck to remove the head or even the hoofs if you wanted to leave the bone in the thighs and make steaks. I like large knives. , sometimes they do require more practice using them to make feather sticks or to wittle a spoon or bowl from wood vs a thinner smaller knife. Now as far as the "survival" aspect of knives, when one chooses a knife for any kind of wilderness use especially if the area you live in or frequent to is more isolated, the wildlife that resides in that area, thats where the size of knife comes to mind. Imo, a survival knife needs to meet my criteria like fire making capabilities, comfortability, edge retention, quality of steel and heat treatment, self defense capabilities, fine carving capabilities. Every one has their preference and techniques they use. Some people only carry an axe, but can achieve all the same results vs one with a knife. It all comes down to skill sets, preference, location, and the tasks expected to be done.