WOW! There sure is a lot of dislike for the 357Sig!
All I can say is my former employer purchased first the Sig 229/357 and then the 239/357, and we loved 'em. I could shoot it as fast and accurately as the Sig 228/9mm, and the boss liked the 357Sig for its flatter trajectory and higher energy at a given distance. They did have to buy ammo by the pallet since it was sporadically available.
I still like it, now in retirement, but have pretty much given up the Sigs (and any DA/SA) because I have considerable problems now with the double action / single action after the first shot, something that never bothered me before during 20 years using them. The M&P has been perfect for me. I've been wondering if my Sigs can be made DAO.
I recently read an article that reported the LAPD as saying they have had great success with the cartridge and are quite happy with it.
All comparisons I have seen show the 9mm, .40S&W and .45ACP as delivering very similar results, so perhaps the 357Sig is not the step up it once was. One of our sons is a LEO. His department issues 9mm Glocks. He has been shooting since he was five and is now a department firearms trainer. He says he feels well armed with the 9mm. Winchester LEO ammo, I think.
Another is professional military (four "tours" in the desert giving his father more grey hair). He is proficient with and seems happy with almost any caliber. I think we all agree hits count more than caliber.
Here are some ballistics from
Ballistics 101 | All the ballistic charts. Finally, in one place
Seems to me the 357Sig has a significant edge over 9mm.
357Sig ballistics:
Buffalo Bore:
125-gr JHP, 564 ft/lb, 1425 fps
Cor-Bon:
125-gr DPX, 505 ft/lb, 1350 fps
Double Tap
125-gr JHP, 584 ft/lob, 1450 fps
Extreme Shock:
115-gr EPR, 410 ft/lb, 1220 fps
Federal
125-gr JHP, 506 ft/lb, 1350 fps
Fiocchi:
124-gr FMJ, 505 ft/lb, 1350 fps.
Grizzly:
125-gr HPXTP, 624 ft/lb, 1500 fps.
Hornady:
124-gr HPXTP, 502 ft/lb, 1350 fps.
147-gr HPXTP, 490 ft/lb, 1225 fps
Remington:
125-gr UMC, 506 ft/lb, 1350 fps.
Speer:
125-gr Gold Dot HP, 506 ft/lb, 1350 fps
Winchester:
125-gr JHP, 506 ft/lb, 1350 fps.
9mm Ballistics:
Buffalo Bore:
124-gr JHP+P, 413 ft-lb, 1225 fps
115-gr TACXP, 500 ft-lb, 1400 fps
Cor-Bon:
115-gr DPX+P, 399 ft-lb, 1250 fps.
125-gr JHP+P, 434 ft-lb, 1350 fps.
Double Tap:
124-gr Bonded Defense JHP+P, 473 ft-lb, 1310 fps.
115-gr JHP+P, 511 ft-lb, 1415 fps.
147-gr JHP+P, 410 ft-lb, 1125 fps.
Extreme Shock:
115-gr EPR, 385 ft-lb, 1182 fps.
124-gr FF, 385 ft-lb, 1182 fps.
Federal:
115-gr JHP, 356 ft-lb, 1180 fps.
124-gr Hyd-Shok, 345 ft-lb, 1120 fps