Allen,
You make a good point about carrying a lighter weight pistol especially having rotor cuff problems. I don't have that problem however the arthritis is sinking into my shoulders. It gets harder to pull on a sweatshirt or reaching around to put a jacket on and pulling the sleeves so it will fit. And absolutely, bullet placement is where it's at. Without proper placement you might as well throw a rock and get the same results. I do have a 9mm Colt combat (all steel) from the late 60's however I don't shoot it as much as I should. I should also say that I like the 1911 platform, and I think it was from our military training. Old habits die hard. If I could afford it, I would venture to say that I would like to own a SR1911 Ruger in 9mm. Though I have only read about the pistol, I have not been able to see one or even hold one in my hands. I have not tried the Extreme Defender round yet so I can't make a comment on how well they work for me. My every day carry round is the Hornady Critical Defense round which I have shot and done some testing. They have good mushrooming effect, holding most of the bullet in tact and penetration is good. I even recovered the plastic nose insert which was surprising. My only reservation, if you want to call it is, after a long day, the 1911 does become heavy, especially with our temps out here. I am of a slim build so I wear my T-shirts outside of my belt so you can't detect any imprint. It doesn't hurt to investigate other calibers and rounds with today's technology, so maybe it's something that I should do more investigation on. I can emphasize with you and your shoulder problems. I have a back problem so pistol weight does have a bearing on me. But again I must admit, I am very partial to the 1911 platform. I have had a couple of Glocks and was totally unhappy with them. Although lighter to carry, I just didn't have the confidence in them that I desired. With my 1911, I also carry a extra round holster. I am not looking for a firefight, I am looking at deterrence and if possible, escape from a bad situation. Of course you realize that this is just my opinion and I neither condemn nor condone other lines of thought.
With all my regards and sincerity,
Tommy