In the Noblesse description on this site, it basically says you do more damage in PvP. Now what I want to know is, does that also imply that debuffs you cast have a greater chance of landing (compared to if everything else was the same, but you WEREN'T Noblesse)?
You won't notice the increased damage, if there even IS any, when being a noblesse.. I sure haven't.. Heard rumours it only apply on battle fields aka. castle sieges.
I actually don't know, and doubt anyone really does. If I were to take a guess though, I would say no. It probably works the same way A grade weapon SA's work, so if you have two weapons, you could give it a test!