My experience is in JKD (Seattle branch). While traveling, I went to one KM class and have looked into it a little since then. It seems like an effective approach. They used basic strikes (they really like the hammer fist) and hit hard, fast and continuously.
It is very technique oriented. If you are being attacked with an overhand knife then do this, if it's under then do that. The problem with techniques (in a lot of systems) is that the person feeding the attack becomes very predicatable and they usually start leaving their hand out as a handle. With that said ... most of the techniques I saw would work because were simple - block, kick, grab, hit, and keep hitting until you knock the snot out of the guy. What's not to love?