If one were to look at a thread to validate a long-ago decision, this would do it.
I have a 2 3/4" stainless Security Six like the one OP posted.
I bought this specific revolver for two reasons:
1. My PPC guns (primary and a back up; the back up never had to take over for the primary though) are both Ruger Six based. That primary has had a lot of rounds fired (albeit .38 wadcutter, not .357) between practice and matches. High but easy miles. It has only ever had one problem (more on that anon), so it has proven Ruger's ability to deliver a reliable revolver. This experience established my history with Ruger DA.
2. Prior to my division (Patrol) in our department acquiring S&W 686s (which I pushed), our issue revolvers were 66s. We had a lot of problems with timing issues with them. When I went through the two week CA POST rangemaster course in 1980 I was on my third 66 by the time I finished the course. The one 66 I really liked, despite the issues, was the 2 1/2" 66. Size, weight and balance were (are) perfect. To get these benefits in a more robust revolver, and with my Ruger experience in mind, I bought a 2 3/4" Security Six. I put on a nylon Hogue Monogrip and took it to the range. I was sold on it with the first shot. That assessment has never varied.
Back to my once-ever failure on my Ruger PPC revolver. Somewhere around ten years ago, after seldom shooting this revolver after retirement, I took it out of the safe to dry fire it. The trigger would not return. I knew the trigger return spring had broken, which disassembly showed to be the case. But this was not a Ruger failure. One of the steps taken to make this into a match revolver was replacement of the stock trigger return spring with a lighter version. It was this light spring that had (finally) broken. I ordered a replacement, and fifteen minutes after I received it the revolver was up and running again. I did note that this replacement light trigger return spring wire was of slightly greater diameter than the one it replaced, so perhaps the aftermarket had learned something in the interim.
I think these are great guns. Glad to see the rest of you are right.