I have several good HK and S&W 40s, a couple of 45ACPs because I kept finding all this nice once fired brass at the range and decided the 3rd Gen S&Ws might be fun since they were showing up cheap (never really liked the 1911), and one 9 because it was a good one (3913) and at the time I bought it, it was cheap.
My opinion is that the 40 is a better round by itself than the summation of the other two.
It's cheaper to shoot than the anemic old 45ACP that needs viagra just to achieve decent penetration, whether you handload or buy factory, and more fun than the wuss little 9, with a snappy feel that says "yep, yep, that's right, I'm bigger, I got more stuff".
If I'm shooting a 9, I might as well be shooting a 38SP revolver; ditto a 45ACP viz-a-viz a 45 Colt.