I've started a new map to see how the dark fog is. It definitely changes the game. Previously you could just run a chain of power poles to a new location and build a factory. Or fly to a new planet, drop in some power and build a new factory.
With dark fog you now have to consider how you're going to defend the area. Chains of undefended power poles can get destroyed and your remote factory shuts down.
Will be interesting to see how feasible it is to eradicate them from your home system as i tech up.