I've read 9mm vs. .45 in articles dating since the 1950s. Today its 9mm vs. 40 vs.45. In the days of only FMJ ammo for autopistols I was convinced that you were foolish to choose a 9mm. Today, I'm not so certain.
I'm still not a big fan of the 9mm Luger, but I no longer consider it inadequate, with the right ammo.
NOTHING works 100% of the time. And, I admit some of the .45 guys actually believe the hype about their chosen round, but a lot of us know what a .45 will do, and what it won't. Some of the bias probably comes from the fact that we won WWI and WWII with the .45, facing guys with 9mms. Therefore, our .45 has to be the better choice, right? Well, yes, I thought so, but not for that reason.
One of the things that irks me a bit is that some 9mm fans today think the 9mm was always what it is now, and don't understand how anyone could choose something else. They never knew the time when 9mms were ALL single stack mag guns (with the exception of the Browning Hi Power). They may know, but I don't think they realize that there was the 9mm, then the 9mm +p, and now 9mm+P+, and how, if the round had been adequate to begin with, the hi pressure versions wouldn't have come about.
Historically speaking (and from my point of view) this didn't happen because the 9mm round was improved, and then people chose it, it happened because people were choosing 9mm and finding out they wanted (or needed) something that worked a little better.
I find it somewhat ironic that while the 9mm has been "uploaded" over the last several decades, the .357 Magnum has been downloaded.
Someone saying how the best 9mm loads equal the .357 from a 4" barrel is not, to me praise for the 9mm, its a sad comment on how far the .357 has fallen.
The 9mm Silvertip that "failed" the FBI in Miami met every requirement then in place for performance. And it still "failed". The FBI chose to use that failure as their scapegoat. The decided to go with the 10mm instead.
Sadly, the 10mm ammo, and the guns then existing, were too hot, and too big for a significant portion of the FBI to maintain their quals with.
The first step taken to correct this was a reduced 10mm load, and the search for a different gun. While this search is going on, S&W created the .40S&W. A round which met the FBI performance specs, AND fitted into a 9mm frame size gun. I won't say it was a match made in Heaven, but it worked pretty well for the FBI, and what works for the FBI is adopted by a lot of police.
The main drawback, as I see it, is that the .40S&W is at max capability to get the desired performance. It is, quite literally a bomb in a small package. If you look at the number of (verifiable) Ka-booms during development of certain guns, you'll probably find the majority of them were in .40S&W.
Recoil? Everyone is different, and different guns feel different. You may find a significant difference between the calibers, I don't, really.
Use whatever you can shoot best, because only hits count, and only hits in the right place WORK. .22 through .45 this holds true.