Well. Yes.
After going through a lot of combat logs, I can see that it "helps".
It heals by about 1,5% of my hp. Adding points beoynd the first increases this by 0,15% per point. So at 5 ranks, it will heal 2% of your health, 1 out of 5 times that your spell lands and isnt resisted.
I think this qualifies it as the worst "working" feat ever.
If it at least procced with EVERY attack - including AoE - then it was less of a laugh - but most likely still too weak for me to place points in.
~~DukeP~~