Cleave and Infernal blow skills

This is more of a concern than a suggestion - Infernal blow seems unbalanced to me.

It seems like initial damage is too small for its mana cost, and you can't really spam it in the combat against masive enemies, and the final damage upon death doesn't make it worthwhile.

I found Cleave far better and more powerful for crowd control than Infernal strike.

What are other people's experience?

And while we are mentioning Cleave, animation for it doesn't really feel like it has hit the enemy - if there is a potential for changing it, please do so.

And also, I am now around level 20 and have not found one single green gem.
Are they known for their rarity?

I've been playing a build using Cleave and Infernal as my main skills and they each have their own place and time.

I have Infernal Blow set up with extra fire damage and Chaos dmg while Cleave is pretty much straight physical damage. When you start finding lots of mobs with resist/reflect it really helps to have the choice between elemental and physical dmg.

Also, Infernal is great for only having to kill crabs once ;)

For me, once I hooked up Melee Physical Damage and Added Fire Damage to Cleave, I dropped Infernal Blow.

I'm a big Cleave fanboy. Ground Slam is good too.

Infernal blow sucks unmodified (changed it asap after getting a different skill).

However, if you potentially go heavily into elemental, fire and burning damage/duration passives, get support gems like increased elemental damage, chance to ignite, elemental proliferation (to spread the burning) than you can do serious AoE damage while retaining a decent single-target attack skill.

So everything is a matter of your chosen build.