My thoughts/observations:
I think it looks overall like quite a sensibly designed airframe. The fuselage looks very good aerodynamically for an aircraft designed for subsonic speeds. The optimum subsonic shape is in fact a water droplet in free fall, which is quite fat. Increased weight, but also increased cabin space!
The traditional horizontal and vertical tail plus the ventral fin (largely preventing prop strikes in this case) is a very sensible approach: thank heavens they haven't opted for any silly fashionable flying wing or canard designs. The wings do look a bit small but similar to a UAV or glider. Nice, efficient high aspect ratio. And lift/drag ratios are generally improving in aircraft design all the time, so I'd think it would have quite an excellent glide for an aircraft of its type. Only the numbers can tell for sure though. The polyhedral wingtips are useful, but also a bit of a trendy fashion thing in my opinion. I think they actually work a bit better inverted but then you can have ground clearance issues.
The main thing I'm sceptical about is the diesel engine pusher arrangement. I'd prefer a more conventional design. Put the prop at the front and save the diesels for trucks, tractors, tanks, trains and subs.
And seeing that they're leaning so heavily towards efficiency, the question is what are they sacrificing in order to attain it? Because everything is always a compromise in aircraft design. How will it compare with competing aircraft that are less efficient but perhaps more practical and capable in other areas? As we move through the 21st Century we're generally seeing the aviation industry in decline, so it will be interesting to see how commercially successful this machine will be, if at all.
For comparison - A successful aircraft, built for an entirely different purpose, with some similar design features - Lockheed U-2:
