as much as i really hate to say this, the last swap meet i went to, there was this guy that was selling used tools. [of course there was. ]
while browsing through his collection, he had some snap-on ratchet box wrenches, as well as some stanley [made in china] versions.
both seemed to be very gently used, and i was astonished at how much smoother the stanley mechanisms felt, compared to the snap-on ones.
the stanley wrenches seemed to also have a closer [shorter ?] degree of movement between teeth.
the bodies of the stanley wrenches were more comfortable in my hands, as well as being polished more than the snap-on wrenches.
as to the long term use between the two brands, i don't have a clue. however, at my age, i wouldn't be afraid to use the stanley's, as i don't wrench for a living.
this is just my observation of a certain comparison between like items.
your mileage will vary.