doesn't seem to be any point to redoing the older levels at higher difficulties, the penalties for doing a lower level seem to negate the benefit of finishing it at a higher difficulty.
I'd suggest using basic turrets and laying down as many fighter bays as you can, seems to be a lot easier than when I was building autoguns, double blasters, and generators as well.
surprising amount of increase in difficulty from levels rated at 10 vs 15 vs 20s, for the 20s the turrets I place get dropped to half health within the first few seconds, usually never lasting more than 15-20 seconds
I get a weird placement error on the huge map, when it's the next day, it tries to center on the area that completed a task (killing zombies, scavenge, reclaim, etc) but the coordinates are off, so it centers on a spot that's still unexplored (black), and will sometimes end up in a spot between two blocks and get stuck shifting between the two blocks until you click drag back to your area.
Odd, Hercule's Grip says Damage +50%, Health +50%. When i try to add it to the Black Dragon, current health 10500, attack 400, it gives +2625 Health, and +100 Attack, half of what I should be getting.