If I can add anything to Kyle's insight it would be the emphasis on intent. If you've follow Kyle's stuff you immediately notice his guys try to throw the ball hard, and I mean really try. Run and gun throws do a great job of training this. Every velocity record that is broken at his facility is wildly celebrated among his clients. With this type of environment and culture it is easy to see why his guys have seen such great velocity improvements.
I think the run and gun stuff can give an unfair representative of velocity programs that implement this tool. All guys want to do is run and gun and see how high they can get the radar gun up to. This, of course, is the fun part. What is missed too often is the part that may not be quite as fun for some: the meticulous study of mechanics, the hours put into the weight room lifting weights, and the hours spent on recovery methods.