For becoming transparent, mods can create a self-moderated thread but the meaning will be the same. A moderator can delete posts even if it is not self-moderated while in a self-moderated topic OP/moderator can do whatever s/he wishes. Won't both be same again?
In self-moderated threads, replies belong to the OP. In other threads, replies belong to the respondents individually. Think carefully about whether you want to reply to a self-moderated topic, as your post may not be given due respect.