There are several parts that make helix spells so worthwhile (at least on NMs lasting more than 60 secs. long).
1. Damage to MP ratio is enormous. Like Hideka said, it is just about equal damage output to Tier V spells but tier V spells cost 3 times as much.
2. Nothing (beyond enmity) stops you from casting nukes while helix is ticking down. Can usually get off about 2-3 spells throughout that duration for 3k each. 4000x3+4000 helix = 15000 damage in 60 secs. Good job! (and get ready to die if mob isn't).
3. Enmity gain is minimal compared to the damage delt. Like casting a very potent tier II or a feeble tier III.
4. Kiting fights don't really allow you to stop and cast massive spells without using alacrity and even then you'll usually get smacked if he isn't gravitied. Helix allows for constant damage while kiting.
So I wouldn't say helix's are in dire need of fixing. Modus Veritas needs a fix more like, and certainly won't oppose Helix II spells. It's sad though, that people don't fully realize the potential damage output of helix spells because they only see the initial lackluster damage.