delphi isn't a no-name brand. they've been around for ages and make good stuff.
i've been known to be wrong before. however, if i'm tasked with NOS ball joints, i'm searching out factory stuff and paying the premium on it. to me, old moogs would fall in between that and what i know is top quality and can get currently, and that's where my price point would be.
if they're less than 15yrs old though, they're likely just as rubbish as the new stuff.