Couldn´t have said it better. High AC monsters in SL FORCE players down the pipe of two or max three weapons at endgame.
For traders it is: S4, Wyrm, Xan shotty and Silverback.
With monsters at manageable AC´s the choices would include every shotgun with a decent MBS. Such as Krutt assault, Home defender, Impressive Presence Shotty(Damn i love that one), just to name a few.
I love my two bags full of toys, but i only use them on RK raids or aliens.
Edit: I did have a comparison of Endgame guns and oldschool shotguns. The Krutt Assault, Vektor dual wielded, and the Vektor dragon are not that far behind on DPM as the endgame guns on low AC. soon as we get into the 20k+ ranges, the performance is poor. A max ql Krutt does actually outperfom The S4 and Silverback with a crit modifier over 45%.