I started my LE career with a .357 magnum, that was fine. When I went to work for the staties it was a .45acp, fine as well. Eight years ago I transferred to a different division and now carry a .40, once again fine. After tweenty three years in LE work and military service before that, that only thing I've determined about pistol caliber is this: I don't care. With modern ammunition the performance gap is largely closed. The common service calibers have their differences, but it all seems largely academic at this point. The deciding factor is my ability to accurately place the projectile on target, not a few milimeters difference in bore size. If carrying a .40 makes you feel like you've strapped on the hammer of Thor than by all means carry one, it's not a bad choice, but don't fool yourself into thinking it gives you some inherent advantage.
The .40 doesn't need to be driven to higher pressure? The .40 IS a higher pressure round all the way around. Forty caliber pistols will wear out sooner than the comparative nine milimeter. This is not vodoo, it's a fact based on physics not wishful thinking. Your .40 won't spontaneously disassemble on you, but shoot it to destruction next to the comparative 9mm and it will poop the bed sooner every time, garunteed. I suspect you don't believe it simply because you've decided not to.
Debating caliber effectivness with those well versed in ballistic science will not result in an harmonious outcome.