I had the QA1 arms on a 69 Coronet (along with everything else they carried: k member, uppers, strut rods, torsion adjusters) And was very pleased with all of it. Sold the car last year. New owner reports everything is still working great and he drives the car a lot.
Now have another set of lowers I intend to put on another 69 project car for the same reason you mentioned: used ones are typically in pretty worn out condition.
I have some 1st hand experience with the folks at QA1, going back to when they were starting to pull stuff back from overseas and start making it in Lakeville, MN. Jim Jordan was the head guy and it was a pleasure to work with him. He died of cancer some years back. I have always been impressed with the staff, their equipment, their attitude, etc.