Why do you need it anyways? Obviously its not worth using in pk since the ap is so low, and when your exping as a sin you barely use pots anyway, spike is like 100 mp, other skills just like 25 & 50 or so, lol.[/b]
It makes minor heal possible without using a single mp pot. So exping is without any pots at all (only stuff like hornets/tyons though).
Also, in Apostle parties and stuff, I use main daggers for damage and when my mana is low, I switch to the mp recov dagger and when I'm full, switch back.
My AD+4 has helped me out a LOT.