Cap was a manufacturer of some front end parts Tubular control arms and k frames. I believe QA1 bought them out and worked on their designs to improve them.
Exactly so. CAP had issues with quality control and at least one welder that didn't know his @$$ from his elbow. The result was probably at least half a dozen instances that I know about of some kind of failure, some of which allegedly caused accidents. That's just what's running around on the internet. Customer service was a bit lacking, and there were some threads on other websites where the owner got in some pretty heated discussions with customers. There was a ton of drama on both sides, and I even was pretty skeptical about one of the failures in particular. But I learned the error of my ways when my own LCA failed.
QA1 bought CAP out a couple years ago, redesigned their products, and re-released them after about a year. The design of the CAP products wasn't bad, but their construction sucked. I wouldn't worry about any of the QA1 parts, I've seen some of the pieces and they were not only well constructed but beefed up pretty significantly as well. The QA1 parts look to be high quality pieces, in accordance to the reputation that QA1 has already established.
The old CAP parts, at least any that were welded together by CAP, should be used only as paperweights or doorstops IMHO.