While it is an interesting question, I think it is based on a false assumption that there is a best solution. As MB says in the podcast all the time, every solution is a compromise. Size, weight, concealability, your skills, training, attitude, etc.
I have been an emergency responded in industry for a long time. What we stress in training for chemical spills, medical responses, etc. is the same as I hear from MB and the trainers he likes. The most critical skills are in order:
1. Awareness
2. Scene Assessment
3. Bias to Action
4. Application of available tools (guns, knives, running away, etc.)
Us guys want to talk about number 4 all the time cause it is cool and that is where your question is aimed. But it is useless without 1-3. In fact the better you are at 1-3 the easier it is to pick a useful tool.
In my experience, 1 responds to constant preaching (Thank You Michael!), 2 responds to scenario drills (mental or physical), 3. is by far the hardest to teach and comes from experience (this is the value of competition) and 4 is about understanding the limits of what you have at hand.
Long winded answer

Joe