The lesson I learned many years ago (fortunately painlessly) is that if there is ever the possibility that you will need to use a gun without having the time luxury to think about each step is that it is important that the gun you have then, and the gun you practice with be the SAME, if not exactly the same gun, the same in their method of operation.
Defensive handguns are in that group for me.
In that sense, every DA revolver works exactly the same way. Semi autos are varied and if you vary the type you carry for defense, odds are high that when you do need it, the one you have won't be the one you know "instinctively".
IN my case, the lesson was taught to me by a pheasant....A friend dropped by, said he had seen a deer up the canyon, but all he had with him was his Browning Sweet 16 shotgun and some bird shot and he wanted to borrow a deer rifle....
So, I loaned him one, and went along, and he gave me his shotgun to carry in case we put up a bird.
Never did see any deer, but did flush a pheasant. Lined out headed straight away, a clout shot, so I mounted the gun, punched the safety off and fired.
Nothing...
actually repeated the process twice more before the bird sailed out of range, punched the safety OFF pulled the trigger,
nothing, not even a click. Chamber WAS loaded, I KNEW that since I did it...
The problem here was the safety. My shotgun was a Winchester model 12, one I had decades of experience with. So what I did, without thinking about it was what was the right thing to do for my model 12, where the safety is in front of the trigger.
Trouble was, I was using my friend's Browning, where the safety was behind the trigger. Acting on instinct (my training) was not the right thing to do for the gun I had in my hands at the time. I think that could be a very BAD thing using a pistol for defense. Pick one kind of operating system, and stick with it. Otherwise, Murphy can visit at the worst possible moment, if you get my drift...