Lots of good thoughts on knife choices. I can say for myself I have been the whole spectrum on knife carry. When I was an active soldier the choice was a rather large fixed blade. I started with the classic Ka-Bar and evolved to a Randall #1 with a 7 in. blade. Military knives have to be more of a weapon as well as a survival/field tool.
After leaving the military behind, I have taken to more practical field knives. A good outdoor knife to me is one that is strong, easy in the hand and easy to sharpen. The blade is always less than 5 inches and has less recurve at the tip. That makes it easier to sharpen and a more useful tool for doing camp chores such as notching stakes or cookpot hangers. That is my perspective based on my tastes and personal experience.
I almost always carry a SAK, Farmer model too, mainly for the tools it provides and the blade is twice the thickness of the standard SAK's.
I carried a multitool while in the Army and sometimes in everyday life. I stopped depending on them after breaking an original Leatherman, USA made. I was not abusing it! I gave the replacement away. I then went to the larger Supertool and had no problems. I later gave the Supertool to a friend in Iraq, he loved it and broke it in two weeks. I sent him a Victorinox Swisstool which he still has 4 years later. I myself own a Wave but I only carry it everyday, except days in the wilderness. I prefer not to carry it in the wild because I don't trust the metal it is made of and I consider it too heavy.
Anyway, that is my take on the knife question. The Ka-Bar is great if you may need a weapon/tool.