It seems like this one has plenty of differing opinions. Suffice it to say, there's never going to be a perfect answer to this one, in ANY scenario, really. It's a true compromise.
I guess I'd have to echo the statement above, that I'd try to retain the element of surprise close up and engage THEN move, or at least draw then move while engaging. But far away, I'd size it up, and if escape or hiding and waiting it out is a valid possibility, then that'd be the way I'd go.