McE,
You've hit on a very good point there. When I was competing many years ago, before electronic timers became affordable and most of us didn't have them, I used to tell myself that I shot a .45 just as well as I shot my 9mm guns, and when the .40 came along, I said the same thing.
Funny how that timer, along with the holes in the target, tells the truth every time, isn't it?
Of course, back then, the situation changed a bit when the weenie loads we had then for the 9mm wouldn't take the steel down, and we had to shoot them more than once.
There's a world of difference nowadays between what you can buy over the counter in 9mm and what you could back then though. In my last years on patrol, I cheerfully carried a 9mm loaded with Gold Dot +P's and felt pretty well armed.
Triggerb,
There is another type of person who is not usually a .40 fan, even though they may shoot it well. That is the police department firearms trainer who has to qualify his cops once or twice a year when they have no interest in guns and they refuse to practice in between, when that trainer has the brass breathing down his neck to get everyone off the range and back on the street. I've been there and always felt that my men and women in that category would have been better served with a 9mm pistol. As the armorer, I was also not a huge fan of having to maintain our department's .40's.
Of course, none of this means that an individual cannot shoot the .40 well, or enjoy it. I say shoot what you like.