Snap on may the leader in 1/4 drive chrome metric universal sockets. They offer a wider selection of sizes, seem to have a narrower and shorter profile than other brands for improved access. The Snap ons will become loose with daily use just like lesser brands especially when used with an air ratchet. I don't really see any difference in 3/8 drive performance across sk, proto, or craftsman versions but, that's just me. I only use the 3/8 drive chrome universal socket if a 3/8 imapct swivel socket won't fit.
I have a set of the Craftsman 3/8 sockets that have been filling a drawer for about 3/4 of their life with half of them having broken drive sides. Have the most recent ones seen a improvement?
The 1/4 Snap-on ones I use have gotten a little loose in their 25+ years, but still work. The newer 3/8 ones have gotten negligibly looser. No breaks though.
Plus the bolt or nut does not stay in,drop and I know the quick fix.Stuff a little bit of grease in so this does not happen.I have a couple Matcos,a 10mm and a 13mm in 1/4 drive which are not cheap.$40.00 a piece and hold up.Chrome swivels tend to bind too.
i like snapon for 3/8 simply because the head side that holds the nut/bolt has a hole in it which comes in hand when you are running down a nut on a stud. that little hole gives you a few more turns than a closed head design
my 1/4 drive set is cornwell. only gripe there is it stops at 14mm.