I'm a semi-professional wrench -- that is I've earned my living in the past turning a wrench but I'm not a certified mechanic and have never tried to become one. I've always been a Craftsman guy and I think for a very good reason: fast tool replacement. My argument for Craftsmen is this: I cannot afford to own duplicates of every tool I own. I am not a rich man, and I must spend as little as possible on my tools but I also must buy tools that will last, because I can't afford to spend the money twice. If I am working and a tool breaks, I will need to replace it immediately so I can continue working. I have multiple ratchets, but I generally have one deep and one shallow socket in each size, and speciality tools I especially have just one of. When a Craftsmen tool breaks I know that as long as it's not after business hours, I can drive straight to Sears and get it replaced. With Snap-On, Mac, etc, my tool gets replaced the next time I track down the Snap-On guy or as long as the postal service takes. What that would mean for me in reality is that if I had to have the tool to keep working, I'd end up going to Sears or the nearest tool store and buying another one anyway. What good is the warranty then?
I've worn out more than my share of Craftsmen ratchets, and rounded out more than my share of sockets. I've bent tools, even sheared a solid breaker bar straight in half before. I know how to use a tool properly, but I also know that sometimes, as a last resort, the only way to accomplish some specific task is to use the tool improperly, to put a giant cheater pipe on it, to beat on it with a sledge. When I have no choice but to do that, at least I know it's gonna be okay if I break the tool because I'll have a replacement in hand in an hour.
Quality is important to me, but replacing something immediately? Equally important.