I have no experience with it, but I'm sure it is fine for what it is intended for, penetrating body armor and helmets, both in handgun and sub-gun configurations, something the standard handgun rounds cannot do.
BUT, in reading early reports of the Fort Hood atrocity, one female soldier attending to the wounded removed her blouse, to use as battle dressing ( gotta give her a BIG thumbs up, as well to all the others who went into "combat mode" mentality!!). Anyway, back to the point, after her blouse was off, she realized she had taken a round, penetrated her torso, with no reaction from her. Not exactly "stopping power". I don't have balistic tables handy, but the FN would equate to what, a service 5.56 @ maybe 500-600 yards ??
Mark