Quote Originally Posted by Anova View Post
Also, disable reduces all damage by 5% (this increases to 10% reduction at lv.44 with the trait). It is essentially virus; and is used as such. When you use Virus or Disable on most bosses, it doesn't matter. If you're raiding, you tend to save disable and virus for specific phases. It depends on the boss and there is no catch-all situation to use it.
Though I don't have hard evidence, I believe this to be the case for Disable. When you're fighting common enemies, the percentages translate into so small numbers that they'd fall within the natural variance of the attacks. But when used on say something big like a raid-wide hit or a tank-buster move, the 10% becomes much more noticeable.

I'm not entirely sure, but I think Disable stack with some if not all the other debuffs like Virus and Rend X, which should make it a very useful tool in more intense encounters.