Raptor or Swarmling Zerglings in HOTS?

Question

One of the first choices in the HOTS campaign is between Raptor and Swarmling Zerglings.

Raptors just look cool and attack faster, but Swarmlings could save a base as they mutate faster and in groups of 3 instead of 2.

What are the advantages of each? What is the best mutation depending on what type of Zergling I chose? What about other abilities that help each? (eg Kerrigan levels)

Mutations

Adrenal Overload: +50% attack speed

Hardened Carapace: Gain an additional 10 hp

Metabolic Boost: +60% movement speed.

Answer 1

You already summed it up rather nice I guess. ;)

I haven't had time to dab too much into the campaign yet to be honest, but it's essentially your decision how you'd like to get the additional damage:

• With the Raptors you'll get more damage and mobility on your existing two Zerglings per egg.

• With the Swarmlings you get more damage in the form of a third Zergling per egg (and essentially faster replacements).

Overall, both should provide you with a comparable damage boost.

If you like micro managment and don't have any issues moving even single units to avoid damage as much as possible, I'd pick the Raptors (especially if you like hit & run attacks). On the other hand, if you prefer the brute force approach, without having to worry about losing a few of your units, then the Swarmling might be the best option for you (because you can replace them faster and you lose less per unit lost).

Answer 2

While Mario's answer does a good job explaining the raw differences between the two types of 'ling, I think it bears consideration the possible synergy of both types as well.

Zergling Reconstitution

For instance, my favorite Kerrigan passive ability is "Zergling Reconstitution". As your zerglings die, you will get them back, at a rate of 10 per 30 seconds.

What this means, in practice, is that you only need to make zerglings once - afterwards, you simply wait for your zerglings to respawn on their own. The combined effect of this is that you will morph very few zerglings in campaign maps.

What this means in practice, is that the Swarmling evolution is of limited use - you can make zerglings fast, and in great numbers... but if your zerglings are continually being reconstituted, there's no real need for either. Reconstituted zerglings are free of resource cost, and do not take up larvae that swarmlings would require. The swarmling's greater numbers are still an advantage (1 more 'ling per moprh), but it's doubtful the 20 or so extra 'lings you'd get over the course of the map would swing the battle much one way or the other. Compared to the bonus damage and leap attack of the Raptor, Reconstitution-heavy strategies have an easy choice.

Banelings!

But even beyond considering reconstitution, there's another idea worth exploring - banelings! Swarmlings let you produce banelings much faster (and at a reduced total mineral cost) than Raptors. If you're a player who's fond of the little, rolling acid-balls, picking swarmlings means more banelings, faster, for less minerals. And while 18 swarmlings on their own might not work as an "Oh @#$*, they're killing my base" button, 18 banelings very well might (and they'll be out more than twice as fast as a Raptor's 12 'ling hail mary). If you're making Zerglings for their explosive relatives, you may find the Swarmlings a better choice, overall.

Answer 3

I will keep it short and somewhat personal.

Tl;dr - Raptor Strain + Metabolic Boost = Winning.

This combination gives you fastest, most mobile and cheapest land unit in early, mid and sometimes in endgame. This combination make winning so easy that it was crazy. Combined with mutalisk for air dominance makes very fast, aggresive and mobile army that I prefer in SC2: HotS.

And you feel something warm inside when you make such unstoppable Zerg swarm.