Did some testing on Life Drain (Dark Blast) here are the results

[Yipp]

First let me explain, trying to decide on the best slotting for Life Drain for my build. LD is in my rotation as a damage spell as it is a high damage spell, with a heal. I used Banished Pantheon sorcerer type mobs for testing (daemons and mummy's etc... have a high resist for Negative Energy).

 

No Enhancements

Heal      112.44

Damage  83.6

 

Heal

3 Enhancements Heal power 42.4% 21.2% 26.5% Heal power (Nictus)

201.4

 

6 Enhancements Heal 3 above + 21.2% & 26.5% Heal power (Nictus Full set)

216

 

Damage

3 Enhancements Damage power 26.5% 26.5% 21.2% Damage Power (Thunderstrike)

139.9

 

6 Enhancements Damage power 3 above + 21.2% 21.2% 26.5% Damage Power (Thunderstrike Full set)

160.92

 

There are of course other reasons to slot one enhancement over another (Defensive bonuses as an example), however this shows clearly the diminishing returns of enhancements.  I knew it existed and have seen it play out before, this test however is interesting to me as it makes me think a little bit more about the choices I make, to think about 6 slotting for set bonuses, and what the losses for doing so especially on a dual use power might be