The sunken colony is now one of the strongest defensive structures in the game. Compared to 1.03, the sunken colony has undergone several new changes. There is now an decrease in the amount of resources required to construct a sunken. Also there is an increase in the amount of damage done. Last and most important, the attack rate of the sunken is far greater than before. Combined with 400 HP, the sunken is able to stop any early rush.
The sunken colony, does slow a Zerg player down, since it takes away from the amount of drones you have, and eats up resources. Your second hatchery can be slowed greatly, if you build too many of these structures. This is similiar to building too many bunkers/turrets for a Terran.
Now any early rush: 3 zealots, 8 zerglings, or 6 marines, will not hurt your base if your sunkens can cover your entire base. So make sure you can protect your buildings and workers, especially those near the vespene gas site. Also Terrans who bunker too close, will be in for a surprise since sunken colonies out range a bunker. Also if you have 2-3 sunkens present when a reaver drops, expect the reaver to be destroyed. Since now, with the increased fire rate, the sunken can fight off a sunken colony. Of course they can always siege your sunkens from long distance, but at least they didn't blow up 10+ drones with one scarab.
Sunkens make a great structure to close off choke points, and can be used to absorb hits. Expect a lot of players to use sunkens, meaning that you can safely expand, contain them, or out produce them.
