Bearing in mind that I am more or less a novice when it comes to shotguns and I have only been to a couple of shotgun matches (they were side matches at IDPA shoots).
My barrel patterns very well, regardless of what I am firing....even the cheap buckshot patterns relatively uniformly. The barrel is a quality barrel, it's just not super fancy.
The security barrel just has a basic brass bead, no fancy sights or anything. I guess you could have some sights installed if you wanted to...
I have shot slugs out of it, and I never do very well with them during the matches...I keep pulling my head up and shooting over the target, but when I sat down and shot some off the bench to figure out what I was doing wrong, the slugs grouped just fine, about 5 inches at 25 yards, and right where they should be. I don't know how much of that was me, the sights, or the weapon, but I am sure those groups will drop a little bit after I get more practice shooting without true sights.
I hope this helped a little bit, there are probably several dozen members who can give you a more complete answer than I, but hopefully this was helpful.