I am
not a good source for Sig 1911 information.

But I do have limited experience and just the briefest of knowledge on the Sig 1911 subject. First is that the very earliest Sig 1911's weren't really made by Sig, they were Caspian (I think? Or was it Essex?) and Sig just
really wanted their name on a 1911 before they were set up to make them. So if the subject is Sig 1911, beware that the earliest really are not.
I had a Sig duo-tone Match Elite for a short time and it was a failure. Best I could tell from digging around and finding MANY conversations, Sig did not do well during the Barackolypse when they ramped up production to meet the irrational demand and their QC was suspect. This pistol came from the middle of that and it showed. It had (for lack of a better term) gouges in the slide near the muzzle -UNDER- the finish, obvious manufacturing goofs. There were also multiple bright spots on the brushed stainless slide that actualy looked like leather holster wear (on a new $1,100 pistol, directly out of the box) These were cosmetic failures only but horribly obvious and this happened on MANY guns and Sig's reply to anyone that called up service was that they were acceptable manufacturing anomalies that don't affect the operation of the pistol and were simply not covered by Sig. Not really even a "sorry", more of a "yeah, we see it. Still works, enjoy it."
The pistol had a VERY short spec chamber. A lot of factory ammo was run through it with no problems but handloads choked it up often. Folks that don't handload can/will (maybe SHOULD) write this off immediately as a non-issue, and that's fine. In fact, I would NEVER contact a manufacturer with this scenario and I did NOT. But the bottom line is that my ammo ran great in three Les Baer pistols, one Ed Brown, two S&W PC guns, maybe a dozen and a half other .45cal pistols... So this short spec chamber was thoroughly ANNOYING, but even I would not call it a failure.
However, the terrific Bomar rear target sight that was
loose in it's dovetail after the second magazine through the pistol was again, unacceptable, on an $1,100 new pistol...
Folks who follow Sig closely and love them will back up the idea that they were in a bit of a free-fall for a period of time and some changes in upper management has most looking toward much better days. I've never been much of a Sig fan on any level, and the only Sig I continue to own and love was made by Hammerli.
IMNSHO, there are far,
far too many great 1911 pistols out there to roll the dice with a Sig. But like any gun... if you have one and have gotten to know, trust and love it, I would never attempt to argue that it isn't a darn good one, and I'm sure Sig has made a truckload of completely terrific 1911 pistols. Pretty sure I'll never own another.