Yes, correct the Notch and others mentioned are double wall. And heavier.
The 19 ounces for the GC and Serenity inner tent after will vary somewhat, just like the weights will also vary with the tarptents. Especially so after seam-sealing. However, for discussion purposes, the general weight disparity will be in the neighborhood.
The guys come on the GC and are included in the weight. Stakes are what the user wants to buy. Can be light or heavy. 6 needed.
I have nothing against the tarptents, and in fact I almost bought one.
But, after the research, I felt that the GC offered more at less weight.
And considering the dual-use nature of the GC, in addition to being lighter in the shelter, I also saved probably a half-pound or more by not having to buy rainwear and a pack cover.