Originally Posted by
kopcap
Here is another way to rationalize ER vs IV.
Lets assume that healing effect of both spells is roughly equal. I actually prefer a 10%heal+10%hot/1min over 10%heal/30sec, but lets assume they are equal.
Lets assume they are both cast off CD.
Lets assume we are reserving Zerker Rage strictly for ER.
Cost of IV over a minute is 20 rage + 2 GCDs, that could had been spent towards SS, SnB or Revenge.
Cost of ER is essentially 2x Zerker Rages = 20 rage. In other words we are paying a similar rage price, but not wasting any GCD's. Yes, we are loosing some dmg. But the extent is arguably insignificant due to GCD advantage.
In addition, it is very reasonable to assume that in real conditions at least 1 every 4 Zerker Rages will be safe to cast because it will happen during ER CD.