Something has to change
I've noticed a few games where the aliens send some small units to attack the power node, or in some instances, gorges have been able to vantage point bile bomb it and easily destroy it. To me, the power node is too important of structure to just be so vulnerable. I'm not concerned about defending one or two (Because I know how to use mines, turrets, ect) but when everything you have relies on them it is difficult to defend. And I think that if a power node goes down, it shouldn't immediately drop the power of structures. Because of the immediate power loss, a game can completely change in the alien favor in a matter of seconds (even is some games where marines have been doing better than Aliens).
I think that instead, when a power node goes it, it should have a small period where structures begin to power down, but don't immediately turn off. Maybe after about 10 or 15 seconds or so. This would give you time as a commander to react and prevent you from losing territory or base so easily.
Power nodes are key to holding Marine territory and because they are so easily destroyed they need to have some balance. Aliens only need to cyst things up and until the marines get flames, doesn't really make a difference because cysts can be grown so easily. I think that if there were a power node 'cooldown' or whatever to allow structures to function for a small time after a node goes down, then there would be more territory balance.
Phillip the Server