I'm going to go along with Allan considering the bullet.  While there were some bad decisions made in the old days--carrying target wadcutters for defense and the like, hopefully the majority of armed citizens today are informed enough to choose a premium self-defense load of some sort.  With the work the ammo makers have put into law enforcement and SD ammo, and the publicity its gotten among shooters, I just don't see those old-time mistakes being made.  Sure, some loads are better than others, but we're talking marginal difference today vs major difference in the old days.  and there just weren't that many good loads in the old days, so we can forgive our for-bearers for not really knowing what to carry.  Today, I think the bottom line is reliability and then accuracy in our personal handguns.  If we want to be picky--I admit I'm an ammo junky so I'm picky, then we can be picky.  But for the fellow or gal who doesn't care to study gelatin tests, look up manufacturers specs, or even do this kind of testing himself, Allan was right when he said choose a good factory defensive load and be happy--or words to that effect.

Do I have a point here?  Yes.  (Surprise! )  Gun Counter clerks and the commandos that hang there, gun writers, gun show presenters--they all have an opinion, and either their livelihood or their interest is based on making a lot out of these questions.  It's fun if you're interested, but you can't rely on other people's conclusions because they all have an axe to grind.  You have to do the work yourself.  If you can't shoot up your own gelatin and don't own a chronograph, that's fine!  most people don't.  But you're better off simply buying a premium load from a premium ammo maker and making sure it works in your gun(s).  Reliability and accuracy, right folks? 

As my wife likes to tell me, "don't sweat the small stuff."  What's the difference?  Carrying a decent caliber is important, which premium ammo you choose is far less important.  Today, the barrel length is far less important.  Bullet composition, bullet style?  Practically meaningless in the grand scheme of things.  

Just don't carry a .380 and think it will always peel a drugged up attacker off you when the worst happens.  It doesn't have the guts when you're NOT going to be in a position to practice perfect, "left eyeball marksmanship."  And that isn't a comment on you, it applies to ALL of us.  If we are ever attacked, our skillset is going to degrade faster than mayonnaise sitting on a picnic table on a hot July afternoon.