I agree, Caleb. I've got one of each; the GP100 has a magnificent trigger job, but the Security Six's is just a bit...better. A bit smoother, with absolutely no perceptible hitches/grit/hesitation/stutters. If it sounds like I'm damning the GP100's job, I'm honestly not-its quite good in its own right, but the Security Six's is clearly...better. I have no idea who performed the work on the Security Six, as I got it used from a reputable gunshop, and also subsequently had Ruger thoroughly go through it. The only thing I've done is have a couple of the chambers polished, all of the chambers chamfered, and replaced the Ruger Target grips it came with with first a set of Hogues, and ultimately with a set of Trausch grips that the late Jacques Trausch was kind enough to customize for me.
For overall handing dynamics I'm slightly preferential towards the GP100 (mine has the full lug and compact grip).
Best, Jon