It just lets you see your post while typing, the same way it will appear when posted. (not linked pictures and such)

I use it. Saves me from hitting Post Preview...cuz I tend to forget to hit Submit Reply if I do that, and lose my posts.

You can change your options by going to UserCp. Then to Edit Options. Scroll the bottom box, which is Miscellaneous Options. Message Interface Options. Click the little menu arrow to choose.

Be sure to click Save Changes any time you make a profile change. (signature, avatar, email....)

You weren't wrong Moi...there is more than one way to eat pie. I like a bite of crust first.