A Question Of Sport - well, Vampirism actually

[gaspode1]

I hadn't noticed this stanza tucked away in the skill tree. It seems, to me, almost too good to be true. As I read the description, you get back more than the cost of the stanza - as long as the cast is successful ie the HP's aren't just taken from the target but are added to the casters pool.

Am I reading this correctly, and are there any wrinkles I should be aware of before I buy. For instance, I had a suggestion that it only works on mobs of a lower level than the caster. Not a stopper but, if true, worth knowing anyway.

Another thought I have is; what happens if you are casting against, say, madakams which have a Reflect Damage defense. Obviously, you will stand the cost of the stanza in casting the spell. However, if reflected, does that mean the HP's are taken from your good self and then given back to your good self (or does the Madakam get them)?

Once again, thanks in advance as I'm sure someone will know whats what here