I don't feel the need to use Drain as RDM or SMN because they already have a healing skill.

But as BLM I noticed some things about Drain that really bothered me:

First, the potency is too low. The other mages have better healing options and usually they can handle themselves (At least with a chocobo on their sides). Even with a chocobo, BLM with Drain and Manawall can't handle some fights like the others do. Paople could say the skill heals and causes damage at the same time, but it doesn't make it good, because DPSing isn't the intent of Drain anyways... I think the potency could even be reduced, but the healing should be increased.

Second, the casting time. Ok, BLM has a speed buff and an insta-cast buff, but I don't want to spend them with Drain... I had a situation the other day where only me as BLM and the healer were left at a 4man dungeon' s boss. I should rely on Drain as Healer would heal himself and rez the rest of the party, but I couldn't because boss interrupted me every time. I wish Drain was instant, so You can Kyte the mobs/bosses/Fates...

What do you guys think?