This is basically a "nothing update" for me. I have little to no interest in Serenity as a plot device and probably won't even touch it or see its specific ending. Maybe if it did give a really decent stat buff, but I probably wouldn't even take the risk.
I even question its use as a role-playing device. Vampire Mila probably would take Serenity since being a vampire is about embracing a sinful lifestyle. However, I can't see Human Mila becoming a druggie, especially if you hand the box of drugs to the guards in that one side-quest. She might not look it, but Mila is a reasonable and responsible vampire hunter.