Originally Posted by
Kerfax
Lucy has it perfectly for the uses of both talents (HA & DP). If damage is random and consistent (that combination of terms makes no sense but bear with it), like Jade Shards, then having DP is as strong a choice as HA in my opinion. HA is much more suited to controlled periods of burst damage, while DP (as long as you're not entirely unlucky) comes up randomly through an encounter. Consistent damage is also where EF shines, so the two can work very well together.
As far as them being amazing together, I'm not sure that it makes a huge difference one way or the other. If you are EF blanketing and toss out 30 1 HP spells, you are rolling the dice 30 times but should only have a (1/3 * 25)% chance of getting an initial DP proc. The alternative would be to toss out 10 3 HP spells and get the full 25% chance of getting an initial proc.