There is one critical problem causing the drop of stacking:
When Frenzy is stacked, casting other skills especially for those with long animation such as rupture, will easily lose the stack unless you cast Frenzy again immediately. This is very annoying.
I suggest that casting other skills should extend the duration of stack like what Frenzy does; or pause the decreasing of stack.
Frenzy stack duration should be part of enhanced, and the stacks should fall off one by one instead of all at once.
I agree. 8 seconds at least and stack falling one by one… Also legendaries so we can play frenzy build.
The only thing blizzard needs to do to make frenzy more viable (ok maybe not the only thing but the single most important thing) is to ADD an effect to battle trance that makes frenzy last 10-15 seconds (variable roll).