135 gr Federal Premium JHP (.40)
vs
165 gr Federal Premium JHP (.45):

.40: 1,190 ft/s, 424 ft-lb
.45: 1,060 ft/s, 412 ft-lb


165 gr Speer Gold Dot JHP (.40)
vs
185 gr Speer Gold Dot JHP (.45)
vs
200 gr Speer Gold Dot JHP +P (.45)

.40: 1,150 ft/s, 484 ft-lb
.45: 1,050 ft/s, 435 ft-lb
.45(+P): 1,080 ft/s , 518 ft-lb


My point? Both are fine calibers. I personally feel many people like .45 because it's a .45. Just like many people like .9mm because its a 9.

I'd take a .357 mag over anything though.