As a wizzy I love this weapon. Personally, I use it to heal myself when I am soloing and get beat up pretty bad. I gate back to nek forest and tank a few orcs until I am full health again, I always have kei for solo'ing so I am close to fom by the the time I am healed, and gate back to whereever I was solo'ing at. Quicker than bw'ing till 50 and sitting there waiting to regen it on its own. PvP players would have a much better use for it though.
All Black Acrylia weapons have a recommended minimum level of 45. That means that if you are below that level you will get no proc, and will see a reduction in the base damage if you equip it. I think the amount of the reduction is based on the difference between your level and the recommended minimum level.
This is not a hard rule, but a good way to ballpark out what benefit you will see from an item below it's recommended level. This does not address the proc issue.
(recommended level/base stat) x your level.
For example this weapon has 11 damage and a recommended level of 45.
45/11 = 4.09... Every 4 levels you would get approximately 1 added to the damage of the weapon until it reaches it's base damage.
Alternatively: (base stat / recommended level) x your level = the amount of the stat you will get per level.
In this case 11/45 = 0.244... You would get approximately 0.25 damage score from the weapon per level.
Like I said, this is a quick way to approximate your results.