Glad to see someone posting some Silat Suffian footage in relation to knife work - Maul is one of the best I've personally seen.
Didn't really like Rob's Systema clip... sorry, Rob I am sure the drills have context, but those methods of evasion will have you cut to ribbons if you don't check the attacking hand. Especially true, IMHO, when looking at the drills where you strike the knife-using opponent - unless you're checking the knife hand, you really need to have your student with the knife follow up with other slashes/cuts/stabs etc.
Otherwise it has the feel of one-step sparring (which has its place, as does slow training), but is a very limited exercise, especially when dealing with knife attacks.