I will start off with the good, as the designs on these are pretty good. The desert side has a nice look to it, without being too busy to cause trouble putting anything on top of it. And the steel plating side gives a nice feel for a metallic hull for being on board a starship of your design.
...HOWEVER
As mentioned before, the size of the squares feel 'off,' they don't line up with the normal 8x10 per folded section that many of us have become accustomed to from our Pathfinder Flip-Mats.
But my biggest complaint is the lines themselves.
Most "basic" terrain flipmats (y'know the ones that don't have buildings and furniture all about) have either subdued gray, or lighter/thinner lines. The lines on this are thick, dark black. When I ran my first scenario using these I started to outline a building on the steel-plate side, and realized that I could not see my regular wet-erase marker as I was drawing, except for the bits where I missed the line a little bit.
As the lines on the map are black, it meant a simple color change wasn't going to fix it. I ended up having to scribble thick line that were wider than the printed lines just to have building and obstacle outlines be visible.
I feel like the image designs are fine, but would like to see these maps without half-squares on the edges that I can't really use, sized & lined up with the folds, and with grids that I can use to guide my straight lines without them being invisible.