This is the first I have heard of this. Not saying I doubt you...I don't, but I never heard of this. Were these the typical stainless mags with the thick plastic baseplate and marked p220-1?
FWIW, I tend to think the bad rep of recent sigs is a bit overstated. I don't doubt that quality control suffered in recent years, and there have been stupid marketing decisions, but I have had few problems and law enforcement agencies have seemed generally happy with their P229, P226 and P220 pistols, despite Sig's cost-cutting. I can also recall S&W revolver problems, S&W 3rd gen alloy frame pistols cracking, Glock Kabooms, Glock 22s that would not function with weapon lights, Glock ejection and extractor problems, Beretta sights coming loose and 96 frame fatigue, Walther P5 cracked frames, etc., etc. I can't really see much difference in my early sigs and my recent ones.