I think sharpened pictures are easier to compare. I think they shoot hand-held too (seen the shadow of the photographer in some other of their wide angle test shots, and not shooting at base ISO for these samyang test shots suggest hand-holding), so I don't think they're really into maximizing the quality in their test shots, unfortunately.
The Samyang has as many lens groups/elements as the Canon TS-E 24II and thus a bit more than the Nikon PC-E, hopefully this means that it's a highly corrected lens which exceeds Nikon PC-E performance so the D800 gets a better tilt-shift lens. But it's not only about design, it's about precision in manufacturing too. It shall be very interesting to see what it can do together with the D800.