OK, let me ask this same question in a different manner.....would you rather have a .45 caliber or a .75 caliber? Would you rather have a .36 caliber or a .65 caliber? That is in effect the difference in performance between FMJ and the better JHP's when used in .45's and 9mm's. I think it should be obvious which has the potential to be more effective. Again, the only two ways to rapidly stop a threat are a direct CNS hit or by making the bad guy bleed out. Well, a round that penetrates well and expands to nearly twice it's original diameter is going to crush far more tissue and tissue crush is the means of achieving rapid bleed out. It's a no brainer which is most effective.
Now in regards to Clint Smith, I think he operates a fine school and is no doubt a very good instructor. But I only consider him an expert at teaching people how to shoot and train in tactics. Because he knows these skills doesn't necessarily make him an expert on ammo. Just like driving a car doesn't make us mechanics. Therefore I would have no problem seeking training under Clint, but I would seek ammo info elsewhere.
Clint uses FMJ for one reason.....he thinks it is more reliable in function. But we all know that any quality modern handgun should feed fine with JHP's and if it won't, then it's not the ammo's fault. If Clint's pistol doesn't function well with JHP, maybe he should consider a different weapon? Just my opinions.
-Charging Handle