So i had to test out this skill for myself since this forum severely lacks info about skill mechanics, instead mostly relying on "this skill is good, this skill is bad, durr".
Anyway I thought this could be comparable to sorcerers surge ability, boy was i wrong. Here's how it is awful:
1. It only works on light and heavy attacks while surge works on everything that crits
2. It has a internal cooldown, meaning it doesn't proc properly with every tick of lightning and resto heavy attacks. Even light attacks with staves can fall under this cooldown. Maybe should have mentioned that in the skill description ZOS?
3. It DOESNT CRIT heal!
4. It reduces your spell power
Unless you have 100k health don't even bother getting anything out of this crap skill.