I have carried a variety of many of the common folding knife brands over the last twenty odd years, spyderco, benchmade, cold steel, and buck brands most frequently. I can honestly say that i have never had one of these US or Japanese made quality knives fail me, or in other words, fall apart or break to the point of not being usable when put to work within their scope of design.
But despite this I am finding myself strapping on a fixed blade on a regular basis now, there is something very reassuring about that hard use tool on your belt that could withstand truly extreme abuse and likely survive to be used again. Now no doubt some "bombproof" folders exist that push the limits of folding knife toughness, but it seems to me that the size and weight of these types, small size and light weight being the two biggest advantages of folders, starts to reach into the upper limit of the law of diminishing returns, and for a small increase in weight you could carry an even more bombproof fixed. (how much "bombproof" you need is subjective I guess)
Nothing against anyones choices, it is awesome to have so many choices, to be sure! I am just going to carry one of each and keep all my bases covered!
A knife can not carve its own handle. - korean proverb
Let the one having no sword sell his outer garment and buy one. - Luke 22:36