Obviously they are knowledgeable however; they can be obnoxious when they claim that their family lineage gives them some magical insight into things that they may not understand i.e catch wrestling, defensive tactics with weapons, etc.
Lack of this knowledge is acceptable but, either dismissing it or claiming it to be part of the Gracie system all along is not.
This is similar to when BJJ first gained notoriety and every other martial art on the planet suddenly had a ground fighting component to their system. Which supposedly was there all along.
They are consistent though. They have a knife defense video that wreaks as bad as this one. I know this is a Jiu Jitsu forum but since I am a tactical weapons instructor, and by no means an expert in Jiu Jitsu, I have a better frame of reference for this.
Basically, the defense shown is shit and will get you killed. You cannot protect the same side regardless of the angle of attack. Unless someone lets you. Has to be a cross body defense.
http://www.youtube.com/watch?v=qNEZS_wBFt8
