Heart of the Swarm Campaign- Kerrigan Abilities: Improved Overlords and Automated Extractors (Level 10)

The Improved Overlord ability is a modest boon to those who like to operate high-cost assault forces as their main method.  By causing overlords to hatch instantly, this ability removes the wait time that some players suffer when they reach their control cap for units and have to add more overlords to compensate.  Additionally, this increases the amount of control each overlord grants by 50%, making them more efficient as well.  This is not the most direct of improvements, as it does not (for instance) increase your limit on maximum control- only the amount granted by each overlord.

By comparison to Zergling Reconstruction, Improved Overlords lacks an actual power value- overlords don’t bring anything to combat, lack unit transport ability during the campaign, and having to buy two-thirds as many of them isn’t as much of a savings in resources by a long shot.  Compared to Automated Extractors, it is a larger overall savings, but not one that you’ll see any real, lasting change to your progress through a mission from.  For those experienced at building up their forces, it winds up meaning very little at all- generally you’ll have started building your overlords before the time you actually need them present, and while the 50% control increase is slightly handy for conserving resources, it just doesn’t have as much of an impact as it could.

Automated Extractors is more useful to people who are bothered by diverting drones for the purpose of harvesting Vespene gas, and operate a faster strategy.  The net resource conservation- generally 150 minerals per Vespene extractor- is considerably smaller than saving 1/3 of all minerals that would be spent on overlords, but if you’re operating a fast game with an inespensive attack force to begin with it will save you a lot more time and effort in the short run.  Again- compared to Zergling Reconstruction, Automated Extractors is a poor option, particularly given that it caters to strategies that tend to rely on zerglings anyways and will benefit more from Zergling Reconstruction.

Overall, this makes Kerrigan’s level 10 abilities a choice between two lackluster resource conservation methods and one fountain of infinite (if somewhat limited production rate) zerglings.  The choice here should be fairly obvious: Zergling Reconstruction if it’s useful, and Improved Overlords if it isn’t- you’ll get more overall effect from Improved Overlords than from Automated Extractors.