This is a succinct smartly written piece about what you would likely need should that rare final exam come your way. It's more important to carry something, then to argue about what to carry.
Again, context is everything. If you are part of a church security team and carrying a J-frame, you would likely be out of luck when Mr. Wantsomefame rambles in with a rifle or you needed to defend your family against a home invasion.
Give it a read..