Ground Slam or Infernal Blow?

Hey, I'm new and struggling a little. I'm playing Mara and not sure if ground slam of infernal blow is better for leveling (1-30ish). OR Which skill will be able to get me endgame and mapping (nemisis league). I'm taking lots of the hp/rests/defensive nodes so i'm not boosting my dps to make sure I survive in the hardcore league.

Just not sure should I play 2 handed ground slam, 2 handed infernal blow, 1+shield GS or 1+shield IB.

Which is better? Why? What is it dependent on?

Thanks in advance, the build I'm thinking right now is
http://www.pathofexile.com/passive-skill-tree/AAAAAgEAxthYYz38UFB8uIzPKS72SF8_VEnnUu8Oud3yL9SPGS4n7dlhrKpXDXKpWfP7qtIhfNnAGqC0ns2QVacwp4QUcRo4Bg7sOAPGY_0pT_0LJa3kIoKbCfYabLUEGYVdxiSqRtc26e0g42rhc4uMna4SaRcccXlmnqmVUWAaMoBWT30B5zboZKMaVWEhhO907XrvYEsFLeLqAdykGRv6Jd-E2V4Tw4bnkayvOlKGYFYEYVKfy1W1r41UkXFN

(Not sure if Avatar fire is selected but I decided against taking that, but still using increased burn/fire for IB, but is GS is better, I can move those nodes.

1-30 ground slam is better, you need melee splash for infernal blow to be good. Later on with larger packs the explosion from infernal blow deals a chunk of your dps.

I myself use ground slam as utility skill, i link it with life gain on hit, endurance charge on stun and stun. With ground slam's reduce stun threshold and stun support gem, i only need to deal small amounts of damage to get stun for endurance charge so i do not need high damage weapon. I use it on weapon with fast attack speed to spam it for charges and life.

Their very different skills, especially when you look at their core mechanics.

Ground slam gives you more defensive options, and is far more flexible, especially when linked to a blue support, with which you can switch between concentrated effect, giving you a massive damage MULTIPLIER (almost x1.7) and increased AOE, giving you off-screen range for defensive kiting.

The range, even with concentrated effect, is still noticable, especially when combined with multistrike - you will almost never be stood there smacking the air.

Infernal blow on the other hand lacks a lot of utility, however has more raw dps potential because of its ability to be scaled through physical damage as well as elemental (fire) damange.

TL;DR - pick one that compliments or polarises your character. Defensive utility vs raw damage.