So Cal...
Carried a Fenix PD36 on a belt holster. I liked the recharging capability via USB-C. Made it quick and easy to recharge from inside the car while running from call to call. Not having to remove the battery to recharge was huge. This was my go to light for years and it held up. I used it as my primary light. Kept a small USB battery pack in my vest with a USB-C cable to recharge...just in case.
Fenix TK 16 carried in a pouch on my outer vest. I liked the brightness it afforded but I did not like having to remove the battery to recharge. When doing a yard search, perimeter, large properties, etc. when its pitch dark at 0200, the combo of brightness and run time was exceptional. I used it as my backup light or if/when I needed more brightness or battery ran low on the PD36.
Maglite ML50L carried in a sap pocket or in my door handle. Although not the brightest light and certainly not the smallest, what it lacked for in brightness it made up for in throw and run time. When running a dog through several properties or doing a search for hours on end, runtime was king. If I knew I was going to be out of my unit for an extended period, I made sure to grab the Mag. Ran rechargeable NiMh C cells.
Fenix LD15R on my vest. Having a compact yet adjustable brightness light facing outward was handy for taking notes, FI's, searching, etc. Some tasks require two hands and although holding a light in your mouth was mentioned in a previous post, have you ever been searching someone and had them evacuate explosive diarrhea all over the place? NOTHING on my person or any of my gear is going anywhere near my mouth thank you very much.
Fenix E01 on my keychain. Sometimes a quick light when using a cuff key or something similar is handy.
Ran Gen 5 Glock 17 MOS with a Streamlight TLR-1HL. Surefire DSF-870 forend on the Rem 870. Old school Surefire M500AB-RD on the AR. The shotty and AR were department issued and those lights/forends were installed and required.
In my war bag I carried a small waterproof pelican case with about a dozen Ni-Mh rechargeable AA batteries, some rechargeable AAA batteries, spare C cell rechargeable batteries, a USB charger, and a few 18650 cells.
With that being said, I've gone through dozens of lights over the years and have finely tuned each and every piece of gear I carried for what specific task I was doing.