Stiletto's Favorite Folding Knife Lock Types & Why

This is for Jeremy Rearick; he wanted to know about the lock-up on the Case Marilla. And, Anton Beukes, He wanted to know if the Demko Knives, AD20.5, had good lock-up or not. I hope this answers their questions and helps them out with making decisions on them. :-) Peace, Stiletto :-)