To sum it all up, there's a time to go vertical and there's a time to go horizontal (and I'm not referring to bedroom gymnastics either).
The Skagit rig or mono and shot presents the fly more or less vertically in the water column and moves the fly more or less "vertically" in the current, only going across current to any great degree as we swing out at the end. Conventional swinging being the horizontal presentation. It's nice to be able to do both on the same river without changing everything up. That's why I'm looking at the SSH lines as a Q&D way of switching between vertical and horizontal presentations as I move down the river.
The lower Grand is a pretty wide river, but as I sit here typing, I'm think of more and more opportunities for vertical presentations on it -- ordered some T-14 last week with no confidence that I'd ever use it, but now I'm not so sure. . . .