Savage, My point exactly!
Questor, The ambi thumb safety is one of the most dangerous devices ever made for a 1911. I have yet to see one that would suit me. Fortunately, I'm a right hander so that isn't an issue. I can't imagen any right hander having an ambi safety on a 1911 or even lefties for that matter.
I carried a Commander for many years as a duty gun. My fellow Agents that were left handed learned "reach under or reach over" techniques to operate the thumb safety and slide lock. Seemed they could draw and shoot just as fast as right handers. Ambis were not allowed because of their potential for disaster.
A safe carry holster for a 1911 must have some basic features. First, it must have a thumb break or snap through where the strap interrupts the hammer as mentioned before. Next, it must totally cover the trigger and thumb safety. Last, the mag release button must be accessible and not be against the side of the holster. I prefer a high ride leather hip holster where the butt of the gun fits in the small of my back with a 30 degree forward tilt. You should be able to stand, sit, drive, lie down, walk, and even run without impediment. You should also be able to draw the gun in all the fore mentioned positions. Cloth, canvas, plastic, and Cordura type fabric are out. A good leather holster can be soaked in a sink then the gun is placed in a plastic baggie and inserted into the holster. Use your fingers to stretch and mold the holster to the shape of the gun and arch of your hip. Let it dry for a day or so. The harder the leather the better. A soft leather or fabric holster will grab the gun when you try to pull it out. Use a belt at least an inch and a quarter wide so it won't crumple when you try to draw. Alessi is my favorite brand.
It bothers me when someone knocks any gun because they haven't been trained properly on how to use it. I see so many shooters think training is standing flat footed and popping at beer cans, though it is a lot of fun. Attending a good combat course will really wake people up. If you carry a gun, you should practice shooting from a draw in the above positions. If your equipment doesn't work right, buy something that will. With the right gear, you will learn to be confident in your system should the need arise.