They chronied only about 1145ish through my G20, but standard deviations were the tightest that I've found. That is not super critical for pistol ammo, but it does impart a sense that they are assembled with tight quality control.
I don't think that the projectile is anything special, but it would probably be a fine personal carry load. Jacket separation is common when fired through various non-scientific stuff, but penetration is reasonable. The round cycles flawlessly in my G20 (but then again so does everything). Cycling is the first priority of any ammo, and the Win ST passes that test.
One thing I did observe, though, is that the felt recoil seemed stout relative to the modest velocities. I was surprised when I ran them over the chrony.