To the OP: The .357 SIG has garnered a good reputation for stopping power and GREAT accuracy.
The .357 SIG is an effort by SIG to have its name associated with a cartridge (like S&W with the .40). Its original marketing was that it duplicated .357 Magnum revolver ballistics (125 grain at 1,400), however, in the P229 it only does about what that famous revolver load did in a 2 1/2 inch K frame. Performance in the P226 is up to revolver standards, however. That is pretty good, but it does it at high ammo cost, crazy high pressure, lower capacity than 9mm (and there are 9mm rounds that are equivalent ballistics - see below), significant blast, recoil, slower follow-up shots and it seems to chew up guns at an alarming rate.
The ."357" SIG is not .357 at all. It is .355, which is 9mm. The .357 SIG is really a 9mm bullet stuffed essentially into a .40 S&W case which has been necked down to 9mm. Ballistically, the .357 SIG is about the same as the Winchester 9mm load known as RA9TA, the 9mm 127 grain +P+. You need only check the ballistics tables to confirm this. Penetration is not significantly different either. A quick look at the tables in the Winchester LE catalog will confirm this.
Texas DPS is switching from .357 SIG back to 9mm, as are many agencies, and although Texas claims it had a glitch with its first batch of M&P 9 pistols, that plan is apparently still on the table, at least as of now. And, of all the federal agencies, only Secret Service uses the .357 SIG across the board, and I think their needs are unique as they may face assassins or assault teams wearing vests, for which they have special ammo that is simply not available to ordinary US law enforcement or regular private citizens.
There is a reason that in the ICE/Homeland Security tests several years ago that the ONLY pistol approved in .357 SIG was the Heckler and Koch brand. The round is punishing, and even the SIG brand of pistol was not approved. The round is punishing on the gun itself. S&W discontinued its M&P in .357 SIG and its SIGMA (SW357VE) version of the .357 SIG was cataloged for only a year or so, although it was quite reliable and accurate.
That said, if you can live with its disadvantages, the .357 SIG will perform as advertised. For me, however, I do not believe it performs so much better than other rounds that the disadvantages are worth it.
EDIT: It was probably not good for the "clown" to "unload" on you, and if he did so, I understand your point in referring to him as a "clown." That said, it is probably best if all shooters could recognize that there is plenty of room under the tent for shooters of all kinds who like calibers of all kinds, and guns of all kinds.