On many forums the debate goes on weather to bug in or bug out, people will argue either way and I try to remind them that its situational and to be prepared you need to plan for either. Likewise some get caught up in making sure they have a PSK and a GHB and a BOB and INCH, and whatever other acronyms they can come up with.
I simply have varying layers of gear and depending on the situation I'm faced with may utilize it as one or more of the acronyms. My "go bag" for example I'll grab and take to the basement during a tornado alert because it has items such as lights that can help out in those situations.
Same with if we would need to bug out or evacuate, depending on the time or situation there are different layers of gear we may take. A suitcase may be our 'bug out bag' for a given situation.