Setback might have been an issue 15 years ago when the round was first commercially available, but its not an issue with current ammunition. That's like telling someone "You shouldn't shoot reloaded 40s in Glocks" because of a few incidents that happened a decade-plus ago.
As far as "inferior round" goes...tell that to the Secret Service & Federal Air Marshals (of note), along to the dozens of other local/state/federal law enforcement agencies that issue the .357 SIG to their officers instead of the 9mm or 40SW.
Just because some government agency is issued something doesnt mean its a good round. Why do you think Glock has so may LEO contracts? Its not because they produced the best gun, but because when you buy the gun they throw in a couple years worth of training ammo as well as a ******************** ton of extra mags, new holsters for everybody, armorers school, etc... Its not limited to only Glock doing that, but they are the most famous for "buying" contracts. Same for a certain caliber of ammo be that 9mm, .40 or .45.
im still going to trust Doc Roberts(him and Doc F are the two most well known ballistics experts at least in the USA of not the world) when he says it is not the best choice out there. His very well known "acceptable pistol duty ammo" threads on AR15.com, M4Carbine, and where ever else he is an active poster, do not even mention .357 Sig.
http://www.m4carbine.net/showthread.php?t=19887