I love 1911s. I love working on 1911s. I've been working on 1911s for the last 26 years, 19 of which have been at my friend's full service gunsmith shop. I've worked on a lot of 1911s over those years, and I do it for free simply because I enjoy it. That said, the only 1911 that I hate working on is anything that says AMT/IAI. Never took one apart that didn't have quality issues. I've come across examples that are accurate or reliable, and on a couple occasions both. That doesn't change the fact that they are poorly made.
I once worked on a good friend's gun turning a sow's ear into a silk purse. I did this because it was the only 1911 his family owned, and his father loved the gun. It had never made it through a full mag in the time they owned it though, and his dad was the original owner..
Things they all have in common are poor machining and poor quality steel. Considering they cost as much used as a new RIA, buying one is not the smartest move. They will almost always have non parallel holes.
The same friend who owns the gunsmith shop is from California, and knew Mr. Sanford personally. He is a machinist, and was around the AMT shop often. He tells me how frames and slides would be placed on equipment to be machined, with metal chips on the fixtures. He said they didn't even bother to clean equipment, which led to frames being canted during drilling operations. He was of the opinion that no AMT existed with parallel pin holes in the frame, nor parallel holes for the rear sight pin on the Hardballer models.
I've told this story here before. The friend who asked me to gussy up his AMT is a good friend, and I agreed to fit a beavertail, match bushing, new safety, trigger, hammer, sear, disconnector, springs, and grips. I also checkered the front strap and mainspring housing. While tuning the extractor for tension, it folded in half under hand pressure, with the metal looking like torn clay. It was like lead, and to this day it baffles me that steel could be so soft. Checkering the front strap and mainspring housing was truly a pleasure, as it was like checkering aluminum. Usually checkering a stainless gun, it goes slower than a carbon steel frame. A checkering file will go through an AMT like butter. I've checkered 3 of these POS guns over the years, and it's always easy.
Anyway, take apart a Hardballer or Government model made by them if you ever come across one. Look for things like warped hammers, non parallel hammer hooks, non parallel rear sights, etc. The rear sight thing can be a serious issue, as the sight hole can be off enough as to cause stress to the pin. I've seen many come through my friend's shop with rear sights that won't stay on. They break pins over and over. The fix is to remove enough material from the sides of the sight so that the sight can sit crooked. Or, you can weld up the pin holes and recut, resulting in a repair and refinish that costs as much as the gun.
When you see people say run, don't walk away from an AMT, there is good reason. There are many who relate their horror stories on the internet. I've seen so many messed up AMTs I feel confident in saying they are the single worst made 1911s ever.