This is what I hope is the final update on my Shield 9. More than two months have passed since my last update, and I have spent most of this time testing various kinds of SD rounds as they became available for purchase. I now have 1000 rounds on my new S&W RSA, and while there has been an occasional glitch, (HST 124 +P rounds wouldn't reliably feed), overall, my Shield has become the reliable, accurate, fun-to-shoot weapon that so many have raved about.
As to the SD rounds, both the Remington Golden Saber 147 and the Hornady Critical Duty 135 +P rounds have performed very well. I've fired 193 consecutive Golden Saber rounds and 150 consecutive Critical Duty rounds without a problem. I'm leaning toward the Golden Sabers because they are more accurate. In fact, they are more accurate than any round, SD or target, that I have ever fired through the Shield. As a result of all of this testing, I now feel that my Shield is trustworthy enough to serve as a carry gun.
Was all the hassle I've been through worth it? You bet.
Am I now a happy Shield owner? You bet.
I may still occasionally update this thread if I feel it's necessary, but right now, I don't see that happening soon. To all of those who wrote in with advice and encouragement, a big, hearty THANKS!