Big and slow , I resemble that statement. What is this groups feelings of 357 sig?
Of the common cartridges, the .357sig is the highest energy short-action pistol caliber on the market at this time. Practice ammo is the same price (sometimes cheaper) than .45acp, and it is not down-loaded like other calibers... so you practice with the same recoil impulse as your carry ammo.
.357sig is designed for carry, it's admittedly impractical as a low-recoil plinking round, since 9mm exists, but when it comes to terminal performance the cartridge delivers with the best of them. 10mm is really the only thing better in an autoloader. It handily matches the performance of .357magnum from a snubby, which has been the standard by which cartridges are judged for decades... It is roughly the equivalent of .38super +p and 9x23win, only with far more choices of factory ammo and guns it can be chambered in.
The common argument is that .357sig is really no better than 9mm +p+... when in reality, few pistols can handle a steady diet of the excessively loaded +p+, so practice is misleading when using std pressure cartridges and carrying +p+. Besides that, 9mm +p+ still falls 100-200fps short of the velocity of .357sig max loads... just like it falls short of .357magnum.
.357magnum has more potential than .357sig, simply due to case capacity and the fact that more revolvers and lever-rifles have the barrel length to get the most out of it. But size for size, the .357sig matches it in any duty load which tests using comparable barrel lengths.
Anyone who admits that .357magnum is head and shoulders above 9mm, but fails to recognize that .357sig is, as well, is simply biased.
Between .357sig and .45acp, the only advantages .45acp has are a larger unexpanded diameter and lower noise. Every other performance and practicality aspect is a win for the .357sig, including the ability to shoot slightly cheaper and more common .40s&w ammo by simply swapping barrels.
So, if you've decided to pay a premium for a powerful SD caliber, pick the one which outperforms.