Of all the major brands I have owned in good quantities, which would be Glock (have owned 6), Beretta (have owned 10), Smith & Wesson (have owned 5), and Sig (have owned 6), Sig has by far been the biggest letdown in terms of reputation vs. quality. I have found Glock and Beretta in particular uniformly excellent. Not perfect, all brands have hiccups, but my personal 16 Glocks/Berettas have been flawless. My Smiths have been nearly as good. My Sigs...well, I had more malfunctions with a recent-production P226 .40 (made in 2014 for North Dakota Highway Patrol) than I have had with all my Glocks and Berettas combined.
I sold all my Sigs except my 229. I like police-marked guns and my 229's marking is awesome. While one of them (my P220R) was excellent, I just did not trust the brand as much as the others I had. If I was choosing an aluminum-framed gun I always chose my Berettas. A quality gun that has run through many rounds has that tangible feeling of confidence when you carry it or raise it to fire that any regular shooter or daily carrier knows, that "This gun has given me thousands of rounds without issue, if I do my job, it will do its job almost certainly" feeling. I never felt that with my Sigs. I was always ready for a hiccup. When I realized that, and I wanted to thin my collection, Sig was the brand I put on the chopping block.
The shitty business practices with the P320 have been the cherry on top that has cemented that decision.
The sad thing is, Sig designs are, for the most part, very good. There's no doubt that a well-made P226 is one of the finest handguns there is. The problem is, you can no longer trust that they're building them right. And as we know from the 1911, if you can't build it right, it's not worth a lot.
Sincerely sorry for your frustrating experience with Sig QC. I hope it all ends up getting squared away for you and running like a champ. If not, I'd go with a Glock MOS or the new Beretta APX with optics so you at least know the company actually sorta gives a shit about the end-user quality.