Sure it could be better, but ease of construction on this is a big thumbs up.
That side angle cut doesn't even look like a straight edge was used. It probably took him just as long to place those tufts as it did to build the thing in the first place.
Visibility is what you are used to. If you've ever driven a delivery truck, or a bus, you can't see out the back or the side. You have to use mirrors. Mirror deletes may be aerodynamic, but for me, the safety trade off isn't worth it without a video replacement.
My Ranger was older, but with the 5 speed I could get 27mpg just by slowing down. I would think 30mpg in this thing would be doable if he did the same.