I'm a big fan of the P60 format, too. Most of my better lights use that system or one directly compatible. I'm a huge fan of Elzetta and Malkoff, and the two work great together (the Bravo and Charlie lights will both accept P60s and ship with a dropin licensed from Malkoff).

Speaking just for myself I think way too much is made of "features" on lights. To me the best feature is a lack of bells and whistles. I'm far enough down the rabbit hole light-wise to know what I want, and I don't want any multi-mode lights that have complicated UIs. My favorite UIs are the ones used by Elzetta and the JETBeam BC lines. They have one button that just does one thing, and two modes switched by twisting the bezel or tailcap respectively. This is ideal for me because they can easily be operated with one hand and will always come on in the mode I want. I'll grant that a multi-mode like the superb HDS would be fine but I like the KISS approach. I like to have a HIGH mode and a LOW mode. Hidden modes are fun but not useful very often. Theoretically I can see how a strobe/SOS could be useful but I don't really want it on my light. It's one more thing to fail or come on in the wrong mode.

I also think that "lumen drag racing" is a waste of time for most people. It would seem that brighter would be better, and sometimes it is, but lumens and/or candela does not tell the whole story. Beam color and throw are perhaps more important than the lumen ratings (especially given how extensively the ratings are "gamed" by vendors). A piercing blue 1,000 lumen light with a very tight spot will measure well and tick all the marketing boxes but it won't be very useful to change a tire or change a fuse. The human eye is more sensitive in the blue range, so it's easy to gain a higher output by biasing the LED blue. But CRI (color rendition index) is important. A more neutral temp around 4,000 K will render colors in a more lifelike manner. Just as an example, imagine you're stalled by the side of the road, looking at the wiring harness of your boat trailer trying to see which wire is which; it's very hard to tell the colors apart under very cool/blue light.

Lastly all the power and brightness in the world is pointless if the light isn't well made and durable. I've found the build quality of some (but not all) of the Chinese lights to be dubious at best. Especially the cheapo off brands. For instance years ago I picked up a bunch of AAA "Black Cat" lights for about $8 each and initially they were great. The color was a bit blue but they were rated at 100 lumens and had very good throw. But one by one every single one of them failed, with the switches going out or acting erratically. It seemed like a good value to pay $8 and get the same output and beam quality as the $20 Streamlight, but not if all eight of them fail within a year!

For most purposes a very durable light with a HIGH mode around 150 real lumens or better and a good "moonlight" or even "firefly" mode, biased around 4000-4500 degrees Kelvin, will get the job done. Just make sure you get a well made light that won't crap out on you.

Lastly, I do have some AA and AAA lights but all my "serious" lights run on CR123A. They're the best built batter around IMO. They pack a lot of power for the size, they're incredibly durable and reliable, and their cold weather performance is terrific. To date I've never known one to leak whereas I've seen dozens of alkaline batteries leak. They also have extremely low self discharge rates, and important consideration for a light that will be stored for long periods for emergency use.