I agree that the willingness to share this knowledge to more than MIL/LE is a good thing. However, I also see that this type of knowledge and training is also another revenue generating division of Magpul Industries.
As you mention, the more one practices and trains the more proficient one becomes. The effects of stress are always present regardless of the above. For those in the know the skills are usable, but they market the courses as something even the beginner can attend and come away an improved shooter. I didn't see such results in the videos. I saw lots of confused faces when having to execute IA's which I feel were over complicated. Even Costa's chamber checks are lacking. His checks are so fast that I can't see how one would be able to distinguish anything from the flash picture of the chamber. Atop of that, viewing the E port isn't feasible under diminished light so its a specialized skill/manual or arms that only works for half of the day. Another issue I have with viewing the E port prior to taking action is during short range engagements. From what I've learned and what I hear from others is that inside 25 yards any failure of the rifle/primary results in a transition to the secondary immediately due to the imminent threat. That being the case, a visual check of the E port in such a situation is a waste of time and movement. Some might say you could/would omit that step in the process when inside 25 yards. A fair answer, but it introduces yet another variable one must process(your range to threat) before acting. If your IA on a failure to fire is tap/tug/rack(with the charge handle) you'll likely fix the issue. For the close range work even an error in judgement leading to your IA of tap/tug/rack will still be faster than observe/tap/tug/rack.
The one guy in the third video demonstrates this very issue. When engaging steel he experiences a stoppage. He clears it, inserts a magazine(much the same way one would when reloading) then fails to tug on the magazine which results in it falling out. He inserts a fresh magazine then proceeds to hit the bolt catch. This does not load the rifle as it is bolt forward on an empty chamber due to the clearance drill. Had he simply executed a reload with the tap/tug/rack he would have solved the issue the first time.
Aside from the above and some other issues I have, my biggest concern is that the skills taught are AR specific. Obviously that is the issue system for the US forces and many of the private contractors but its not a guarantee either. Learning two, three, or four separate manual of arms is time consuming and only adds the potential for error.
TDC