I like these concrete questions - here's what the knife's going to be used for and where, and here are the choices. Not "which one of the three should I chose...", baselessly.
Civilian carry - PM2, no question - a nice slicer, comfortable handle, the strongest lock imaginable, slim profile, weak tip. Slices limes and tomatoes easily. Fast deployment and good SD knife.
Military service/deployment - Sere, undoubtedly - a fighting knife, stronger blade, strong tip, stronger construction (minus the lock). Geometry of the blade makes it intended for much harder use. Strong, military knife.
That's what I'd choose, without a second thought.