My first experience with Mag lights, close to 50 years ago, still lives today, but has multiplied. My EMS bat belt behind the left hip, has an ancient Surefire M-3 with cannulated brezel, in front of which is a ring for a 4 D Mag light. When you work nights, the cops aren't always around, and cop or not, the flashlight is likely in your hand, when things go south, and you may not have an opportunity to access better right just then.
I always have my pocket lights, but walking into the unknown, unsupported as it were, I'll still choose that Mag light.
I live in NY, the "tools" I can keep access to in public is limited. The 2 AA mini resides in my left rear pocket, it's my medical pen light, best I've found, and bright enough to see what I need to see, but not blinding to the patient, when checking pupils. The 5 D that sits between me and the door in my car, serves the same purpose, it did for thousands of officers, it lights the dark, the shadows, and puts a potent defensive tool in the hand. A 5 D guards my side of the bed, and a 4D sits next to me as I type this. We can't carry ASPs, night sticks, billys, fish bats, jacks/saps or Kali sticks, so the flashlight has to fill that roll, God forbid. I can't walk around with the flashlight, nobody else does, and that attracts attention of the wrong kind, that's the roll of my walking stick. And the walking stick has in common with the deployed flashlight, averse any other commonly available weapon, it's already in your hand.
BTW, the D sized lights make better clubs, the C sized make better sticks. Unfortunately Mag in their wisdom don't make anything bigger then 5 C any more.
Regards, Jim