Look at reviews - as many as you can - from people who have used whatever PV you're interested in before buying. Also, look at he APV forum and see which devices seem to be creating the most issues for their users and avoid those.
Some items will definitely be better built than others, perhaps even if they DO use aluminum threading. I don't know from firsthand experience as my higher end stuff has steel threading.
Really, the more complaints about an item, the more you'll know which to avoid. If there are very few about that item, then it's a good bet unless no one owns one....LOL