This one stands out first for me, Jay, because during the time I was studying JKD, my instructor made a point of how it cuts out any time lag. Lee wasn't into the classical approach to MA when he was designing Jeet Kune Do, and the classical is pretty much, as I see it, block then strike. If you keep practicing it that way, training hours that way, you'll do it that way with the time lag built in. During that time, you're a target. With the simultaneous approach, which is not hard to learn, it just shouts out "common sense." I remember working with a partner who had two focus mitts, one for the parry and the other for the simultaneous attack (punch), and then we'd switch. It surprised me how quickly it can be caught on to. Really nothing revolutionary here actually. In my opinion this stems from Bruce's background in Wing Chun and such. Basic stuff and hardly a thing that JKD is alone in advocating.