Will the sheets become public, incidentally? I tend to make sure I know exactly who and what I'm working with in an RP. I think it helps to work out interaction and stuffs beforehand.

It also helps people not accidentally reduplicate primary character traits when they make their own character, by double-checking that nobody else has used those traits. Obviously I've already sent in my sheet so that's not a factor, but it may come in handy for others. :)