I don't care how good you think you are there is still more to be learned. Or how good you are, you can improve. One can take the same class 2-3 or more times and learn something each and every time. Why? because you are more ready and open to see and learn things that go over your head in earlier classes as your skill level increases. One thing I really like about SI is the instructors are there not only to teach you what they know but to learn from the student as will. Even they know there is more to learn.
Those who act or tell me how good or how much training they have had I tend to tune out. Those who ARE GOOD don't have to tell you their greatness you will know by watching their action and manner.
Been there done that type training many times . It is all good but when the day comes It may not go as planned. Most important thing is do something.
Lot of people making pretty good cash running these course they may be worth while for some but not a requirement for everyone.
Still comes down to good old Army training
Speed, Surprise and Violence of action
Move fast,make a decision quickly to do something
Surprise them with your action it will throw them off their game
Go nuts scare the life out of them hold nothing back don't quit.