This came up at our table recently. I will be paraphrasing, as I am AFB at the moment, but I believe we get the general gist of things...
Cool basically states it applies to initiative when the individual has had plenty of time to anticipate and/or plan out an ambush. Situations of that nature.
Vigilance, on the other hand, is all about being surprised or caught completely unawaress. Being flatfooted and the like.
But I find most situations are neither. Or somewhere in between, to be more specific.
Example 1: Sure you didn't plan out maticulously exactly how you'd walk into the cantina, or know exactly how many badies are in there. But neither were you unaware of their presence. You walk in looking to start a rukus. What skill?
-or-
Example 2: You are standing at the cantina bar and a few toughs step in from outside. You can see they are clearly armed and looking to tussle. They immediately raise their blasters and everyone on both sides commence to shooting. What skill?
Thoughts? Discussion? How do you do it?