To seam allow or not to seam allow, that is the question.

I am working on a super cute new coat pattern.  I have come to the point where I must decide to either add seam allowance to the pattern or to not add seam allowance to the pattern.  What are your preferences?  When purchasing a pattern do you like the seam allowance to already be there, or do you like to add your own seam allowance after making necessary alterations?

And while you ponder your answer....a picture of a day, not so long ago, when I wasn't even considering coats...or seam allowance for that matter.