I like flippers on knives that are designed around/for them. If it's an afterthought addition to a knife, it's usually cannon fodder for a marketing strategy. However, if and when a knife has been a "flipper" from day 1, it can be extremely beneficial. A flipper is inherently ambidextrous. A flipper is also easier to find and manipulate than any hole or thumbstud design. If you have any firearms background, a flipper is often a substitute "trigger". There are many advantages of a flipper. There again however, sometimes manual flippers that aren't designed around the flipper...are more trouble than they're worth. All of the KAI flippers I've had contact with have been remarkable. In fact, a knife equipped with a flipper and speedsafe is basically a triggered switchblade instead of a button operated one. If you're looking at getting into a flipper, I would highly recommend a LEEK, it was actually my first KAI knife, and I gave it all kinds of hell and it just kept taking it.