In the matters (dilemma's?) of trigger safeties VS manual safeties, engineering differences in terms of whether the striker is "half cocked" while the gun is being carried, the question of DA "only" designs VS designs which revert to SA after the first shot...Myself, I find it quite mind-boggling that all of those (and more) things get discussed (debated?) as often as they do and have been for as long as they have, when the answer to all of it comes down to one rather simple thing:
To paraphrase the late Col. Cooper...at it's core, adding a DA feature to a semi-auto side arm "is an ingenious solution to a non-existent problem".
Just to expound on that a bit...as I recall, the perceived 'problem' was that carrying a 'cocked 'n locked' SA semi-auto was so scary to look at that many believed that it must somehow be inherently unsafe, and/or that that the average gun owner/shooter was too stupid to switch-off a thumb safety at the proper time.
Also as I recall, it was S&W whom first capitalized on those fears, which of course prompted other manufacturers to follow along with their own similar (or different) designs, and so forth and so on, right on up until the point we are at today...which is also to say that most all of the so called "improvements" we've seen in semi-auto side arms were not only born from misunderstanding/ignorance/fear, but to a large degree, a need to address (real) problems which simply did not exist with the SA/hammer-fired guns which were being replaced...
just something to think about, that's all...no offense meant to anyone.
That's all I know about that.
I'll return you now to your regularly scheduled programing.
DGW