Well basicaly it is because i got the Luminous Tanga (finaly a top grade one) i started wondering but i decide to lvl it anyway.
Haven't reached Lvl 4 or 5 yet but watching the blows when the 5% Pattack triggers i believe is a good choice
the only CON until now is that it needs a normal attack to trigger the buff so i had to modify my macro to get advantage of it, just a small cost on SS non significant to even mention it
I also believe that the P Attcak on the dagger is very underestimated in fron of the Crit Dmg
time will show as i keep trying to get a Luminous Ari also as a second one