I've used tools professionally my whole life. Most of my stuff is Craftsman, some Proto, and a few other assorted brands.
There is no doubt in my mind that the Snap-On tools are top-notch. Beautifully polished, look great all lined-up in the drawer. But I also don't believe they are any more durable than my Craftsman hand tools. In all the years of heavy use the only Craftsman tool I broke was a 3/8 drive 9/16 deep-socket. It was replaced, no questions asked.
Occasionally when I need to 'build' a certain multipurpose wrench by welding together parts of other wrenches . . . I've cut apart some I purchased at Harbor Freight, made in India, that were highly polished and looked 'almost' as nice as name-brand tools. I've tested them with a hardness tester and they compare with the quality stuff also. They cost a fraction of even Craftsman.
I also once bought a large set of no-name sockets, both metric and SAE, from some outfit [can't remember where] for $5. Would never use them on a day-to-day basis . . . but put them in my truck for emergency. What a joke. The first time I used them they proved to be dead soft, total crap.
Stanley now owns many brands . . . among which the most well known is Proto. Don't recall the other names at the moment.
Purchase the best you can afford. Take pride in their use. Don't loan them <g>.
DON