I think Henry had this in the works for at least 4 years, so I'm sure it's well thought out.
Personally I don't find it nearly as aesthetically pleasing as the Moment 1P or the Scarp 2P, but it's a victim of geometry. If I owned one, perhaps I would name it "Big Bertha".
> BTW, the second vestibule is something I would sacrifice
> for a significant weight savings
Well the Force Ten Helium Carbon 200 Tent has one vestibule:
It's probably more like a 1.5 person tent.
Going larger, the Vaude Power Lizard SUL 2-3P has a wider floor than the TarpTent and weighs a claimed 44 oz:
In addition to comparing tents with similar pole structures, it's interesting to compare tents of similar weights. The GoLite Imogene UL 3P comes to mind, which gives a lot more floor area, but less ventilation options. The Big Agnes Copper Spur UL2 is just about the same weight too.