Overall, I'm pleased with mine. I have several guns/barrels chambered in .357SIG and have been shooting my personal reloads in this caliber for over 3 years. For some strange reason, this gun/barrel combination does not like my reloads, i.e., many of the rounds will not allow the slide to go fully forward ino battery. What makes this situation even more strange, I have another .357SIG Bar-Sto barrel for my Springfield Armory XD40 and it functions perfectly. Oh well, I guess I'll figure it out someday, but until then, I've ordered 500 rounds of "canned heat" from Georgia Arms.
When shooting CCI Blazers (now discontinued in .357SIG, BTW), my accuracy was much better with this Bar-Sto barrel than with the stock .40 Auto barrel.
I own two .40 Auto P99s, and have two of the .357 Sig barrels, one for each, distinguishable by serial number. I have put about 300 rounds through one of them, and it has been flawless and accurate. I am always looking forward to my next range session with this pistol.