I figure that it's my life that I'm concerned with and I'll pick what makes me feel comfortable. I sell guns at a store and I've seen people buy everything from a .380 to .50 for bear handguns, to each their own. The people that chose the .380 were an older couple that felt that they didn't really want to kill a brown bear, they just wanted to scare it and their "gun expert" friend recommended that caliber - whatever. I've heard just about ever silly assumption that anybody could ever come up with.
Trigger pull on a revolver isn't going to add enough time to your response to even be concerned with. A Glock 20 has a 5-6 pound pull weight from the factory, my S&W 329P has a 6 pound pull weight in single action and around 9 pounds in double action and I practice cocking the gun as I draw it from my chest rig so my first shot is a single action shot. As for the length of time it takes to pull the trigger on my double action vs. a semi-auto gun, well that's pretty minimal too because I do practice a lot, I can average 2 well aimed shots in 3 seconds, I can rattle all 6 shots off in about 5 or 6 seconds but my groups at 15 feet will be about 15 inches. I can't shoot quite as well as Jerry Miculek (he can shoot 6 rounds of 180gr .44mag from a S&W 629 in
just over 1 second) but I suspect that I wouldn't do much better with a Glock 20 than what I can do with the 329P. Technique and skill will have more to do with how long it takes you to respond than the mechanical operation of the gun. With the adrenaline pumping you wont even notice the difference between the two pistols.
The only things being said that I agree with by the semi-auto people is that if you should use the gun that you can handle best, as long it's more powerful than a .380.