Paging Jeff and Mikki Martin or Dan Strametz!!!
Who practices? What is it's efficacy in real life situations, as opposed to a Cage Fight?
Brand X is a certified KM training facility. I take a couple of classes a month. It seems pretty darned effective, and as Matt points out it teaches the mindset of at least fighting for survival. I'm sure some folks come out with a false sense of confidence but I think those people would be prone to such in any SD training.
Krav gives real world tools to deal with dangerous situation. Drills in the basic concepts:
Identify the danger, remove the danger, counter attack, get the F outta there. (Again, I am not an expert) I watched the Brand X Black Belt (Kenpo) tests and the way BX blends the Self Defense mindset into all their classes you could really see the application of both Krav and Kenpo principles during the very intense last portion of the test.