Zoom in on the pressure doors, wide & tall enough to get a medium size ship through (7 bricks high, maximum 21 studs wide).
I'm pretty satisfied with the colour scheme.
The side door is big enough for minifigs. I suppose it could be used on it's own in other MoCs.
I really like the angle the keypad makes.
Round the back so you can see the, er, sturdy construction.
Next thing is to make them able to slide up & down.