i've got craftsman, genius, gray, gearwrench (1/4") harbor freight, and sk. i've found myself using 3/8 semi-deeps more than any other, and that set is sk. 2nd most used is 1/2" deeps (craftsman) tied with 3/8 swivels (genius). both sk and craftsman (these are older US-made ones) are excellent. i haven't inspected/used the non-US craftsman impacts, so can't comment if they are the same. the genius swivels are not great. functional, but the collar for the swivel is significantly larger than some competitors. i have non-swivel genius that are fine (3/4).
short version, i think any of the brands (probably including the craftsman non-US made ones and harbor freight) are fine. make sure they are CR-MO (not CR-VA), and move along. swivels it may pay to buy the craftsman/matco non-pin type as their design produces a narrower product.
if you are using them all day, every day, they all wear out. nature of the beast, the drive end will wallow out given enough time. for most DIY folks, any of the brands will last essentially forever.
ahm